[Mac] WebKit contains dead source code for OS X Mavericks and earlier
https://bugs.webkit.org/show_bug.cgi?id=152462

Reviewed by Alexey Proskuryakov.

Source/bmalloc:

* Configurations/DebugRelease.xcconfig: Removed definition of MACOSX_DEPLOYMENT_TARGET for
  OS X 10.9.

Source/JavaScriptCore:

- Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
  that became uniform across all OS X versions as a result:

* Configurations/DebugRelease.xcconfig:
* Configurations/FeatureDefines.xcconfig:
* Configurations/Version.xcconfig:

* API/JSBase.h: Removed check against __MAC_OS_X_VERSION_MIN_REQUIRED that was always true.

Source/ThirdParty/ANGLE:

* Configurations/DebugRelease.xcconfig: Removed definitions of MACOSX_DEPLOYMENT_TARGET for
  OS X 10.8 and 10.9.

Source/WebCore:

- Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
  that became uniform across all OS X versions as a result:

* Configurations/DebugRelease.xcconfig:
* Configurations/FeatureDefines.xcconfig:
* Configurations/Version.xcconfig:

- Removed support for animating default buttons:

* rendering/RenderButton.cpp:
(WebCore::RenderButton::RenderButton): Removed m_default initialization.
(WebCore::RenderButton::styleDidChange): Removed checking for animating default button and
  starting the animation timer.
(WebCore::RenderButton::timerFired): Deleted.
* rendering/RenderButton.h: Removed m_timer and m_default member variables
* rendering/RenderTheme.h:
(WebCore::RenderTheme::defaultButtonHasAnimation): Deleted.
* rendering/RenderThemeMac.h: Deleted override.
* rendering/RenderThemeMac.mm:
(WebCore::RenderThemeMac::defaultButtonHasAnimation): Deleted.

- Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
  never getting compiled:

* accessibility/mac/WebAccessibilityObjectWrapperMac.mm:
* editing/mac/DictionaryLookup.h:
* editing/mac/DictionaryLookup.mm:
* html/canvas/WebGLDrawBuffers.cpp:
* loader/DocumentLoader.cpp:
* loader/cache/CachedFont.cpp:
* loader/cocoa/DiskCacheMonitorCocoa.h:
* page/cocoa/SettingsCocoa.mm:
* platform/Scrollbar.cpp:
* platform/cocoa/MemoryPressureHandlerCocoa.mm:
* platform/cocoa/NetworkExtensionContentFilter.h:
* platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm:
* platform/graphics/cg/ImageSourceCG.cpp:
* platform/graphics/cocoa/FontCacheCoreText.cpp:
* platform/graphics/cocoa/FontCascadeCocoa.mm:
* platform/graphics/mac/GraphicsContext3DMac.mm:
* platform/mac/NSScrollerImpDetails.h:
* platform/mac/ScrollAnimatorMac.mm:
* platform/mac/ScrollViewMac.mm:
* platform/mac/ScrollbarThemeMac.mm:
* platform/mac/ThemeMac.mm:
* platform/mac/WebCoreFullScreenPlaceholderView.h:
* platform/mac/WebCoreFullScreenPlaceholderView.mm:
* platform/network/cf/CookieJarCFNet.cpp:
* platform/network/cf/ResourceRequest.h:
* platform/spi/cf/CFNetworkSPI.h:
* platform/spi/cocoa/CoreTextSPI.h:
* platform/spi/cocoa/NSButtonCellSPI.h:
* platform/spi/cocoa/NSColorSPI.h:
* platform/spi/cocoa/QuartzCoreSPI.h:
* platform/spi/mac/LookupSPI.h:
* platform/spi/mac/NSFontSPI.h:
* platform/spi/mac/NSImmediateActionGestureRecognizerSPI.h:
* platform/spi/mac/NSPopoverSPI.h:
* platform/spi/mac/NSSharingServicePickerSPI.h:
* platform/spi/mac/NSSharingServiceSPI.h:
* platform/spi/mac/TUCallSPI.h:
* platform/sql/SQLiteDatabase.cpp:

Source/WebInspectorUI:

- Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
  that became uniform across all OS X versions as a result:

* Configurations/Base.xcconfig:
* Configurations/DebugRelease.xcconfig:
* Configurations/Version.xcconfig:

* Scripts/copy-user-interface-resources.pl: Removed code to delete Images/Legacy.

* UserInterface/Images/Legacy: Removed this empty directory.

Source/WebKit/mac:

- Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
  that became uniform across all OS X versions as a result:

* Configurations/DebugRelease.xcconfig:
* Configurations/FeatureDefines.xcconfig:
* Configurations/Version.xcconfig:
* Configurations/WebKitLegacy.xcconfig:

- Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
  never getting compiled:

* WebCoreSupport/WebInspectorClient.mm:
* WebView/WebDynamicScrollBarsView.mm:
* WebView/WebHTMLView.mm:
* WebView/WebImmediateActionController.h:
* WebView/WebImmediateActionController.mm:
* WebView/WebView.mm:
* WebView/WebViewData.h:
* WebView/WebViewData.mm:
* WebView/WebViewInternal.h:

Source/WebKit2:

- Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
  that became uniform across all OS X versions as a result:

* Configurations/BaseTarget.xcconfig:
* Configurations/BaseXPCService.xcconfig:
* Configurations/DebugRelease.xcconfig:
* Configurations/FeatureDefines.xcconfig:
* Configurations/Version.xcconfig:
* Configurations/WebKit.xcconfig:

- Removed the definition of BUNDLE_LOCALIZATION_KEY:

* Configurations/WebContentService.Development.xcconfig:
* Configurations/WebContentService.xcconfig:

- Added CFBundleFollowParentLocalization set to true:

* WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-OSX.plist:
* WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-iOS.plist:
* WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX-10.9-10.10.plist:
* WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX.plist:
* WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-iOS.plist:

* WebKit2.xcodeproj/project.pbxproj: Removed the “Add CFBundle Localization Info.plist Key”
  script build phases from the Web Content Service targets.

- Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
  never getting compiled:

* DatabaseProcess/mac/com.apple.WebKit.Databases.sb.in:
* NetworkProcess/cocoa/NetworkProcessCocoa.mm:
* NetworkProcess/mac/com.apple.WebKit.NetworkProcess.sb.in:
* Platform/IPC/mac/ConnectionMac.mm:
* Platform/IPC/mac/ImportanceAssertion.h:
* Platform/mac/MenuUtilities.h:
* Platform/mac/MenuUtilities.mm:
* Platform/mac/StringUtilities.h:
* Platform/mac/StringUtilities.mm:
* Shared/API/Cocoa/WKFoundation.h:
* Shared/EntryPointUtilities/mac/XPCService/XPCServiceMain.Development.mm:
* UIProcess/API/Cocoa/WKViewPrivate.h:
* UIProcess/API/Cocoa/WKWebView.mm:
* UIProcess/API/Cocoa/WKWebViewPrivate.h:
* UIProcess/API/mac/WKView.mm:
* UIProcess/Cocoa/WebProcessPoolCocoa.mm:
* UIProcess/Cocoa/WebViewImpl.h:
* UIProcess/Cocoa/WebViewImpl.mm:
* UIProcess/Launcher/mac/ProcessLauncherMac.mm:
* UIProcess/mac/PageClientImpl.mm:
* UIProcess/mac/WKImmediateActionController.h:
* UIProcess/mac/WKImmediateActionController.mm:
* UIProcess/mac/WebInspectorProxyMac.mm:
* WebProcess/WebPage/FindController.cpp:
* WebProcess/WebPage/WebPage.cpp:
* WebProcess/com.apple.WebProcess.sb.in:
* config.h:

Source/WTF:

* Configurations/DebugRelease.xcconfig: Removed definition of MACOSX_DEPLOYMENT_TARGET for
  OS X 10.9.

- Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
  never getting compiled:

* wtf/FeatureDefines.h:
* wtf/MainThread.h:
* wtf/OSObjectPtr.h:
* wtf/Platform.h:
* wtf/mac/DeprecatedSymbolsUsedBySafari.mm:
* wtf/spi/darwin/XPCSPI.h:

Tools:

- Removed definitions of MACOSX_DEPLOYMENT_TARGET and WEBKIT_SYSTEM_INTERFACE_LIBRARY for
  OS X 10.9:

* DumpRenderTree/mac/Configurations/DebugRelease.xcconfig:
* LayoutTestRelay/Configurations/DebugRelease.xcconfig:
* MiniBrowser/Configurations/DebugRelease.xcconfig:
* TestWebKitAPI/Configurations/DebugRelease.xcconfig:
* WebKitTestRunner/Configurations/DebugRelease.xcconfig:

- Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
  never getting compiled:

* DumpRenderTree/mac/TextInputController.m:
* MiniBrowser/mac/BrowserWindowController.m:
* TestWebKitAPI/Tests/mac/AttributedString.mm:
* WebKitTestRunner/mac/EventSenderProxy.mm:

WebKitLibraries:

* libWebKitSystemInterfaceMavericks.a: Removed.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@194318 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/API/JSBase.h b/Source/JavaScriptCore/API/JSBase.h
index 4a1a257..b91743c 100644
--- a/Source/JavaScriptCore/API/JSBase.h
+++ b/Source/JavaScriptCore/API/JSBase.h
@@ -136,7 +136,7 @@
 
 /* Enable the Objective-C API for platforms with a modern runtime. */
 #if !defined(JSC_OBJC_API_ENABLED)
-#define JSC_OBJC_API_ENABLED (defined(__clang__) && defined(__APPLE__) && !defined(BUILDING_GTK__) && ((defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1090 && !defined(__i386__)) || (defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE)))
+#define JSC_OBJC_API_ENABLED (defined(__clang__) && defined(__APPLE__) && !defined(BUILDING_GTK__) && ((defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && !defined(__i386__)) || (defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE)))
 #endif
 
 #endif /* JSBase_h */
diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
index 0f5f5c2..a3f517a 100644
--- a/Source/JavaScriptCore/ChangeLog
+++ b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,19 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        - Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
+          that became uniform across all OS X versions as a result:
+
+        * Configurations/DebugRelease.xcconfig:
+        * Configurations/FeatureDefines.xcconfig:
+        * Configurations/Version.xcconfig:
+
+        * API/JSBase.h: Removed check against __MAC_OS_X_VERSION_MIN_REQUIRED that was always true.
+
 2015-12-19  Benjamin Poulain  <bpoulain@apple.com>
 
         [JSC] Streamline Tmp indexing inside the register allocator
diff --git a/Source/JavaScriptCore/Configurations/DebugRelease.xcconfig b/Source/JavaScriptCore/Configurations/DebugRelease.xcconfig
index 91e815d..f2b5fa1 100644
--- a/Source/JavaScriptCore/Configurations/DebugRelease.xcconfig
+++ b/Source/JavaScriptCore/Configurations/DebugRelease.xcconfig
@@ -28,7 +28,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-MACOSX_DEPLOYMENT_TARGET_macosx_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_macosx_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_macosx_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_macosx_101200 = 10.12;
diff --git a/Source/JavaScriptCore/Configurations/FeatureDefines.xcconfig b/Source/JavaScriptCore/Configurations/FeatureDefines.xcconfig
index 29e9f10..e364b1b 100644
--- a/Source/JavaScriptCore/Configurations/FeatureDefines.xcconfig
+++ b/Source/JavaScriptCore/Configurations/FeatureDefines.xcconfig
@@ -35,12 +35,7 @@
 ENABLE_ACCELERATED_2D_CANVAS = ;
 ENABLE_ACCELERATED_OVERFLOW_SCROLLING[sdk=iphone*] = ENABLE_ACCELERATED_OVERFLOW_SCROLLING;
 ENABLE_ATTACHMENT_ELEMENT = ENABLE_ATTACHMENT_ELEMENT;
-ENABLE_AVF_CAPTIONS[sdk=iphone*] = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS[sdk=macosx*] = $(ENABLE_AVF_CAPTIONS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_AVF_CAPTIONS_macosx_1090 = ;
-ENABLE_AVF_CAPTIONS_macosx_101000 = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS_macosx_101100 = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS_macosx_101200 = ENABLE_AVF_CAPTIONS;
+ENABLE_AVF_CAPTIONS = ENABLE_AVF_CAPTIONS;
 ENABLE_CACHE_PARTITIONING = ENABLE_CACHE_PARTITIONING;
 ENABLE_CANVAS_PATH = ENABLE_CANVAS_PATH;
 ENABLE_CANVAS_PROXY = ;
@@ -76,12 +71,7 @@
 ENABLE_ENCRYPTED_MEDIA[sdk=macosx*] = ENABLE_ENCRYPTED_MEDIA;
 ENABLE_ENCRYPTED_MEDIA_V2[sdk=macosx*] = ENABLE_ENCRYPTED_MEDIA_V2;
 ENABLE_FETCH_API = ENABLE_FETCH_API;
-ENABLE_FILTERS_LEVEL_2[sdk=iphone*] = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2[sdk=macosx*] = $(ENABLE_FILTERS_LEVEL_2_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_FILTERS_LEVEL_2_macosx_1090 = ;
-ENABLE_FILTERS_LEVEL_2_macosx_101000 = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2_macosx_101100 = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2_macosx_101200 = ENABLE_FILTERS_LEVEL_2;
+ENABLE_FILTERS_LEVEL_2 = ENABLE_FILTERS_LEVEL_2;
 ENABLE_FONT_LOAD_EVENTS = ;
 ENABLE_FULLSCREEN_API[sdk=macosx*] = ENABLE_FULLSCREEN_API;
 ENABLE_GAMEPAD[sdk=macosx*] = ENABLE_GAMEPAD;
@@ -89,11 +79,7 @@
 ENABLE_GEOLOCATION = ENABLE_GEOLOCATION;
 ENABLE_HIDDEN_PAGE_DOM_TIMER_THROTTLING[sdk=macosx*] = ENABLE_HIDDEN_PAGE_DOM_TIMER_THROTTLING;
 ENABLE_ICONDATABASE[sdk=macosx*] = ENABLE_ICONDATABASE;
-ENABLE_SERVICE_CONTROLS[sdk=macosx*] = $(ENABLE_SERVICE_CONTROLS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_SERVICE_CONTROLS_macosx_1090 = ;
-ENABLE_SERVICE_CONTROLS_macosx_101000 = ENABLE_SERVICE_CONTROLS;
-ENABLE_SERVICE_CONTROLS_macosx_101100 = ENABLE_SERVICE_CONTROLS;
-ENABLE_SERVICE_CONTROLS_macosx_101200 = ENABLE_SERVICE_CONTROLS;
+ENABLE_SERVICE_CONTROLS[sdk=macosx*] = ENABLE_SERVICE_CONTROLS;
 ENABLE_INDEXED_DATABASE = ENABLE_INDEXED_DATABASE;
 ENABLE_INDEXED_DATABASE_IN_WORKERS = ;
 ENABLE_INDIE_UI = ENABLE_INDIE_UI;
@@ -106,16 +92,10 @@
 ENABLE_INPUT_TYPE_TIME[sdk=iphone*] = ENABLE_INPUT_TYPE_TIME;
 ENABLE_INPUT_TYPE_WEEK[sdk=iphone*] = ENABLE_INPUT_TYPE_WEEK;
 
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS[sdk=iphone*] = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS[sdk=macosx*] = $(ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_1090 = ;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101000 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101100 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101200 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
+ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
 
 ENABLE_WIRELESS_PLAYBACK_TARGET[sdk=iphone*] = ENABLE_WIRELESS_PLAYBACK_TARGET;
 ENABLE_WIRELESS_PLAYBACK_TARGET[sdk=macosx*] = $(ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_1090 = ;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101000 = ;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101100 = ENABLE_WIRELESS_PLAYBACK_TARGET;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101200 = ENABLE_WIRELESS_PLAYBACK_TARGET;
@@ -128,7 +108,6 @@
 
 ENABLE_MAC_GESTURE_EVENTS = ;
 ENABLE_MAC_GESTURE_EVENTS[sdk=macosx*] = $(ENABLE_MAC_GESTURE_EVENTS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR)_WITH_INTERNAL_SDK_$(USE_INTERNAL_SDK));
-ENABLE_MAC_GESTURE_EVENTS_macosx_1090_WITH_INTERNAL_SDK_YES = ;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101000_WITH_INTERNAL_SDK_YES = ;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101100_WITH_INTERNAL_SDK_YES = ENABLE_MAC_GESTURE_EVENTS;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101200_WITH_INTERNAL_SDK_YES = ENABLE_MAC_GESTURE_EVENTS;
@@ -148,11 +127,7 @@
 ENABLE_MEDIA_CONTROLS_SCRIPT = ENABLE_MEDIA_CONTROLS_SCRIPT;
 ENABLE_MEDIA_SESSION = ;
 
-ENABLE_MEDIA_SOURCE[sdk=macosx*] = $(ENABLE_MEDIA_SOURCE_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_MEDIA_SOURCE_macosx_1090 = ;
-ENABLE_MEDIA_SOURCE_macosx_101000 = ENABLE_MEDIA_SOURCE;
-ENABLE_MEDIA_SOURCE_macosx_101100 = ENABLE_MEDIA_SOURCE;
-ENABLE_MEDIA_SOURCE_macosx_101200 = ENABLE_MEDIA_SOURCE;
+ENABLE_MEDIA_SOURCE[sdk=macosx*] = ENABLE_MEDIA_SOURCE;
 
 ENABLE_MEDIA_STATISTICS = ;
 ENABLE_MEDIA_STREAM = ENABLE_MEDIA_STREAM;
@@ -170,12 +145,7 @@
 ENABLE_QUOTA = ;
 ENABLE_REQUEST_ANIMATION_FRAME = ENABLE_REQUEST_ANIMATION_FRAME;
 ENABLE_REQUEST_AUTOCOMPLETE = ;
-ENABLE_REMOTE_INSPECTOR[sdk=iphone*] = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR[sdk=macosx*] = $(ENABLE_REMOTE_INSPECTOR_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_REMOTE_INSPECTOR_macosx_1090 = ;
-ENABLE_REMOTE_INSPECTOR_macosx_101000 = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR_macosx_101100 = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR_macosx_101200 = ENABLE_REMOTE_INSPECTOR;
+ENABLE_REMOTE_INSPECTOR = ENABLE_REMOTE_INSPECTOR;
 ENABLE_RESOLUTION_MEDIA_QUERY = ;
 ENABLE_RUBBER_BANDING[sdk=macosx*] = ENABLE_RUBBER_BANDING;
 ENABLE_CSS_SCROLL_SNAP = ENABLE_CSS_SCROLL_SNAP;
@@ -185,12 +155,7 @@
 ENABLE_SVG_FONTS = ENABLE_SVG_FONTS;
 ENABLE_SVG_OTF_CONVERTER = ENABLE_SVG_OTF_CONVERTER;
 
-ENABLE_TELEPHONE_NUMBER_DETECTION[sdk=iphone*] = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION[sdk=macosx*] = $(ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_1090 = ;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101000 = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101100 = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101200 = ENABLE_TELEPHONE_NUMBER_DETECTION;
+ENABLE_TELEPHONE_NUMBER_DETECTION = ENABLE_TELEPHONE_NUMBER_DETECTION;
 
 ENABLE_TEMPLATE_ELEMENT = ENABLE_TEMPLATE_ELEMENT;
 ENABLE_TEXT_AUTOSIZING = ;
@@ -219,12 +184,7 @@
 ENABLE_WEB_REPLAY_macosx_Release = ENABLE_WEB_REPLAY;
 ENABLE_WEB_SOCKETS = ENABLE_WEB_SOCKETS;
 
-ENABLE_WEB_TIMING[sdk=iphone*] = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING[sdk=macosx*] = $(ENABLE_WEB_TIMING_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_WEB_TIMING_macosx_1090 = ;
-ENABLE_WEB_TIMING_macosx_101000 = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING_macosx_101100 = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING_macosx_101200 = ENABLE_WEB_TIMING;
+ENABLE_WEB_TIMING = ENABLE_WEB_TIMING;
 
 ENABLE_XSLT = ENABLE_XSLT;
 
diff --git a/Source/JavaScriptCore/Configurations/Version.xcconfig b/Source/JavaScriptCore/Configurations/Version.xcconfig
index 7ec9d0b..8f2b69e 100644
--- a/Source/JavaScriptCore/Configurations/Version.xcconfig
+++ b/Source/JavaScriptCore/Configurations/Version.xcconfig
@@ -35,7 +35,6 @@
 // The system version prefix is based on the current system version.
 SYSTEM_VERSION_PREFIX[sdk=iphone*] = 8;
 SYSTEM_VERSION_PREFIX = $(SYSTEM_VERSION_PREFIX_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-SYSTEM_VERSION_PREFIX_macosx_1090 = 9;
 SYSTEM_VERSION_PREFIX_macosx_101000 = 10;
 SYSTEM_VERSION_PREFIX_macosx_101100 = 11;
 SYSTEM_VERSION_PREFIX_macosx_101200 = 12;
diff --git a/Source/ThirdParty/ANGLE/ChangeLog b/Source/ThirdParty/ANGLE/ChangeLog
index abb66e2..54ac8e6 100644
--- a/Source/ThirdParty/ANGLE/ChangeLog
+++ b/Source/ThirdParty/ANGLE/ChangeLog
@@ -1,3 +1,13 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        * Configurations/DebugRelease.xcconfig: Removed definitions of MACOSX_DEPLOYMENT_TARGET for
+          OS X 10.8 and 10.9.
+
 2015-12-03  Anders Carlsson  <andersca@apple.com>
 
         Remove Objective-C GC support
diff --git a/Source/ThirdParty/ANGLE/Configurations/DebugRelease.xcconfig b/Source/ThirdParty/ANGLE/Configurations/DebugRelease.xcconfig
index 009901f..ae915ce 100644
--- a/Source/ThirdParty/ANGLE/Configurations/DebugRelease.xcconfig
+++ b/Source/ThirdParty/ANGLE/Configurations/DebugRelease.xcconfig
@@ -5,8 +5,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-MACOSX_DEPLOYMENT_TARGET_macosx_1080 = 10.8;
-MACOSX_DEPLOYMENT_TARGET_macosx_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_macosx_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_macosx_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_macosx_101200 = 10.12;
diff --git a/Source/WTF/ChangeLog b/Source/WTF/ChangeLog
index 3f96a3a..7544710 100644
--- a/Source/WTF/ChangeLog
+++ b/Source/WTF/ChangeLog
@@ -1,3 +1,23 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        * Configurations/DebugRelease.xcconfig: Removed definition of MACOSX_DEPLOYMENT_TARGET for
+          OS X 10.9.
+
+        - Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
+          never getting compiled:
+
+        * wtf/FeatureDefines.h:
+        * wtf/MainThread.h:
+        * wtf/OSObjectPtr.h:
+        * wtf/Platform.h:
+        * wtf/mac/DeprecatedSymbolsUsedBySafari.mm:
+        * wtf/spi/darwin/XPCSPI.h:
+
 2015-12-17  Sukolsak Sakshuwong  <sukolsak@gmail.com>
 
         [INTL] Implement Collator Compare Functions
diff --git a/Source/WTF/Configurations/DebugRelease.xcconfig b/Source/WTF/Configurations/DebugRelease.xcconfig
index f89fd79..c0b9a1a 100644
--- a/Source/WTF/Configurations/DebugRelease.xcconfig
+++ b/Source/WTF/Configurations/DebugRelease.xcconfig
@@ -27,7 +27,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-MACOSX_DEPLOYMENT_TARGET_macosx_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_macosx_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_macosx_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_macosx_101200 = 10.12;
diff --git a/Source/WTF/wtf/FeatureDefines.h b/Source/WTF/wtf/FeatureDefines.h
index 77391da..5982baa 100644
--- a/Source/WTF/wtf/FeatureDefines.h
+++ b/Source/WTF/wtf/FeatureDefines.h
@@ -200,7 +200,6 @@
 #define ENABLE_FULLSCREEN_API 1
 #endif
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 #if !defined(ENABLE_REMOTE_INSPECTOR)
 #define ENABLE_REMOTE_INSPECTOR 1
 #endif
@@ -208,7 +207,6 @@
 #if !defined(ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS)
 #define ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS 1
 #endif
-#endif
 
 #if !defined(ENABLE_SMOOTH_SCROLLING)
 #define ENABLE_SMOOTH_SCROLLING 1
diff --git a/Source/WTF/wtf/MainThread.h b/Source/WTF/wtf/MainThread.h
index 65692da..20cf1cb 100644
--- a/Source/WTF/wtf/MainThread.h
+++ b/Source/WTF/wtf/MainThread.h
@@ -84,17 +84,8 @@
 void initializeMainThreadToProcessMainThreadPlatform();
 #endif
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED == 1090
-WTF_EXPORT_PRIVATE void callOnMainThread(void (*function)(void*), void* context);
-WTF_EXPORT_PRIVATE void cancelCallOnMainThread(void (*function)(void*), void* context);
-#endif
-
 } // namespace WTF
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED == 1090
-using WTF::cancelCallOnMainThread;
-#endif
-
 using WTF::callOnMainThread;
 #if PLATFORM(COCOA)
 using WTF::callOnWebThreadOrDispatchAsyncOnMainThread;
diff --git a/Source/WTF/wtf/OSObjectPtr.h b/Source/WTF/wtf/OSObjectPtr.h
index b8babf3..feddf62 100644
--- a/Source/WTF/wtf/OSObjectPtr.h
+++ b/Source/WTF/wtf/OSObjectPtr.h
@@ -30,25 +30,6 @@
 #include <wtf/Assertions.h>
 #include <wtf/StdLibExtras.h>
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-
-#if __has_include(<os/object_private.h>)
-#include <os/object_private.h>
-#endif
-
-#if OS_OBJECT_USE_OBJC
-@class OS_object;
-typedef OS_object *_os_object_t;
-#else
-typedef struct _os_object_s *_os_object_t;
-#endif
-
-extern "C" _os_object_t _os_object_retain(_os_object_t object);
-extern "C" void _os_object_release(_os_object_t object);
-
-#endif
-
-
 namespace WTF {
 
 template<typename T> class OSObjectPtr;
@@ -57,29 +38,13 @@
 template<typename T>
 static inline void retainOSObject(T ptr)
 {
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000 || PLATFORM(IOS)
     os_retain(ptr);
-#else
-#if OS_OBJECT_USE_OBJC_RETAIN_RELEASE
-    [ptr retain];
-#else
-    _os_object_retain((_os_object_t)ptr);
-#endif
-#endif
 }
 
 template<typename T>
 static inline void releaseOSObject(T ptr)
 {
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000 || PLATFORM(IOS)
     os_release(ptr);
-#else
-#if OS_OBJECT_USE_OBJC_RETAIN_RELEASE
-    [ptr release];
-#else
-    _os_object_release((_os_object_t)ptr);
-#endif
-#endif
 }
 
 template<typename T> class OSObjectPtr {
diff --git a/Source/WTF/wtf/Platform.h b/Source/WTF/wtf/Platform.h
index 591818c..b7ed5a8 100644
--- a/Source/WTF/wtf/Platform.h
+++ b/Source/WTF/wtf/Platform.h
@@ -1000,11 +1000,11 @@
 #define HAVE_AVFOUNDATION_VIDEO_OUTPUT 1
 #endif
 
-#if PLATFORM(IOS) || (PLATFORM(MAC) || (OS(WINDOWS) && USE(CG)) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1080)
+#if PLATFORM(IOS) || PLATFORM(MAC) || (OS(WINDOWS) && USE(CG))
 #define HAVE_AVFOUNDATION_MEDIA_SELECTION_GROUP 1
 #endif
 
-#if PLATFORM(IOS) || ((PLATFORM(MAC) || (OS(WINDOWS) && USE(CG))) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1090)
+#if PLATFORM(IOS) || PLATFORM(MAC) || (OS(WINDOWS) && USE(CG))
 #define HAVE_AVFOUNDATION_LEGIBLE_OUTPUT_SUPPORT 1
 #define HAVE_MEDIA_ACCESSIBILITY_FRAMEWORK 1
 #endif
@@ -1034,13 +1034,13 @@
 #endif
 
 #ifndef HAVE_QOS_CLASSES
-#if PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#if PLATFORM(COCOA)
 #define HAVE_QOS_CLASSES 1
 #endif
 #endif
 
 #ifndef HAVE_VOUCHERS
-#if PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#if PLATFORM(COCOA)
 #define HAVE_VOUCHERS 1
 #endif
 #endif
@@ -1064,7 +1064,7 @@
 #define USE_MARKER_REMOVAL_UPON_EDITING 1
 #endif
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
 #define USE_INSERTION_UNDO_GROUPING 1
 #endif
 
diff --git a/Source/WTF/wtf/mac/DeprecatedSymbolsUsedBySafari.mm b/Source/WTF/wtf/mac/DeprecatedSymbolsUsedBySafari.mm
index 41a158f..38b2be3 100644
--- a/Source/WTF/wtf/mac/DeprecatedSymbolsUsedBySafari.mm
+++ b/Source/WTF/wtf/mac/DeprecatedSymbolsUsedBySafari.mm
@@ -39,29 +39,6 @@
 
 namespace WTF {
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED == 1090
-WTF_EXPORT_PRIVATE void callOnMainThread(const Function<void ()>&);
-WTF_EXPORT_PRIVATE void lockAtomicallyInitializedStaticMutex();
-WTF_EXPORT_PRIVATE void unlockAtomicallyInitializedStaticMutex();
-
-void callOnMainThread(const Function<void ()>& function)
-{
-    callOnMainThread(std::function<void ()>(function));
-}
-
-static StaticLock atomicallyInitializedStaticMutex;
-
-void lockAtomicallyInitializedStaticMutex()
-{
-    atomicallyInitializedStaticMutex.lock();
-}
-
-void unlockAtomicallyInitializedStaticMutex()
-{
-    atomicallyInitializedStaticMutex.unlock();
-}
-#endif
-
 #if (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED < 101200) || (PLATFORM(IOS) && __IPHONE_OS_VERSION_MIN_REQUIRED < 100000)
 WTF_EXPORT_PRIVATE void callOnMainThread(void (*function)(void*), void* context);
 WTF_EXPORT_PRIVATE void cancelCallOnMainThread(void (*function)(void*), void* context);
diff --git a/Source/WTF/wtf/spi/darwin/XPCSPI.h b/Source/WTF/wtf/spi/darwin/XPCSPI.h
index 089c250..dd09c8f 100644
--- a/Source/WTF/wtf/spi/darwin/XPCSPI.h
+++ b/Source/WTF/wtf/spi/darwin/XPCSPI.h
@@ -79,16 +79,8 @@
 #include <xpc/private.h>
 #endif
 
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MAX_ALLOWED >= 1090
-#define CONST_ON_IOS_AND_ON_OR_AFTER_MAC_OS_X_VERSION_1090 const
-#else
-#define CONST_ON_IOS_AND_ON_OR_AFTER_MAC_OS_X_VERSION_1090
-#endif
-
-EXTERN_C CONST_ON_IOS_AND_ON_OR_AFTER_MAC_OS_X_VERSION_1090 struct _xpc_dictionary_s _xpc_error_connection_invalid;
-EXTERN_C CONST_ON_IOS_AND_ON_OR_AFTER_MAC_OS_X_VERSION_1090 struct _xpc_dictionary_s _xpc_error_termination_imminent;
-
-#undef CONST_ON_IOS_AND_ON_OR_AFTER_MAC_OS_X_VERSION_1090
+EXTERN_C const struct _xpc_dictionary_s _xpc_error_connection_invalid;
+EXTERN_C const struct _xpc_dictionary_s _xpc_error_termination_imminent;
 
 EXTERN_C const struct _xpc_type_s _xpc_type_array;
 EXTERN_C const struct _xpc_type_s _xpc_type_bool;
@@ -140,11 +132,9 @@
 EXTERN_C mach_port_t xpc_dictionary_copy_mach_send(xpc_object_t, const char*);
 EXTERN_C void xpc_dictionary_set_mach_send(xpc_object_t, const char*, mach_port_t);
 
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 EXTERN_C void xpc_connection_set_bootstrap(xpc_connection_t, xpc_object_t bootstrap);
 EXTERN_C xpc_object_t xpc_copy_bootstrap(void);
 EXTERN_C void xpc_connection_set_oneshot_instance(xpc_connection_t, uuid_t instance);
-#endif
 
 #if OS_OBJECT_USE_OBJC_RETAIN_RELEASE
 #if !defined(xpc_retain)
diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 0161d88..4de1abf 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,73 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        - Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
+          that became uniform across all OS X versions as a result:
+
+        * Configurations/DebugRelease.xcconfig:
+        * Configurations/FeatureDefines.xcconfig:
+        * Configurations/Version.xcconfig:
+
+        - Removed support for animating default buttons:
+
+        * rendering/RenderButton.cpp:
+        (WebCore::RenderButton::RenderButton): Removed m_default initialization.
+        (WebCore::RenderButton::styleDidChange): Removed checking for animating default button and
+          starting the animation timer.
+        (WebCore::RenderButton::timerFired): Deleted.
+        * rendering/RenderButton.h: Removed m_timer and m_default member variables
+        * rendering/RenderTheme.h:
+        (WebCore::RenderTheme::defaultButtonHasAnimation): Deleted.
+        * rendering/RenderThemeMac.h: Deleted override.
+        * rendering/RenderThemeMac.mm:
+        (WebCore::RenderThemeMac::defaultButtonHasAnimation): Deleted.
+
+        - Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
+          never getting compiled:
+
+        * accessibility/mac/WebAccessibilityObjectWrapperMac.mm:
+        * editing/mac/DictionaryLookup.h:
+        * editing/mac/DictionaryLookup.mm:
+        * html/canvas/WebGLDrawBuffers.cpp:
+        * loader/DocumentLoader.cpp:
+        * loader/cache/CachedFont.cpp:
+        * loader/cocoa/DiskCacheMonitorCocoa.h:
+        * page/cocoa/SettingsCocoa.mm:
+        * platform/Scrollbar.cpp:
+        * platform/cocoa/MemoryPressureHandlerCocoa.mm:
+        * platform/cocoa/NetworkExtensionContentFilter.h:
+        * platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm:
+        * platform/graphics/cg/ImageSourceCG.cpp:
+        * platform/graphics/cocoa/FontCacheCoreText.cpp:
+        * platform/graphics/cocoa/FontCascadeCocoa.mm:
+        * platform/graphics/mac/GraphicsContext3DMac.mm:
+        * platform/mac/NSScrollerImpDetails.h:
+        * platform/mac/ScrollAnimatorMac.mm:
+        * platform/mac/ScrollViewMac.mm:
+        * platform/mac/ScrollbarThemeMac.mm:
+        * platform/mac/ThemeMac.mm:
+        * platform/mac/WebCoreFullScreenPlaceholderView.h:
+        * platform/mac/WebCoreFullScreenPlaceholderView.mm:
+        * platform/network/cf/CookieJarCFNet.cpp:
+        * platform/network/cf/ResourceRequest.h:
+        * platform/spi/cf/CFNetworkSPI.h:
+        * platform/spi/cocoa/CoreTextSPI.h:
+        * platform/spi/cocoa/NSButtonCellSPI.h:
+        * platform/spi/cocoa/NSColorSPI.h:
+        * platform/spi/cocoa/QuartzCoreSPI.h:
+        * platform/spi/mac/LookupSPI.h:
+        * platform/spi/mac/NSFontSPI.h:
+        * platform/spi/mac/NSImmediateActionGestureRecognizerSPI.h:
+        * platform/spi/mac/NSPopoverSPI.h:
+        * platform/spi/mac/NSSharingServicePickerSPI.h:
+        * platform/spi/mac/NSSharingServiceSPI.h:
+        * platform/spi/mac/TUCallSPI.h:
+        * platform/sql/SQLiteDatabase.cpp:
+
 2015-12-18  Antti Koivisto  <antti@apple.com>
 
         Cache redirects as separate entries
diff --git a/Source/WebCore/Configurations/DebugRelease.xcconfig b/Source/WebCore/Configurations/DebugRelease.xcconfig
index ccc96ae..2623153 100644
--- a/Source/WebCore/Configurations/DebugRelease.xcconfig
+++ b/Source/WebCore/Configurations/DebugRelease.xcconfig
@@ -28,7 +28,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-MACOSX_DEPLOYMENT_TARGET_macosx_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_macosx_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_macosx_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_macosx_101200 = 10.12;
diff --git a/Source/WebCore/Configurations/FeatureDefines.xcconfig b/Source/WebCore/Configurations/FeatureDefines.xcconfig
index 29e9f10..e364b1b 100644
--- a/Source/WebCore/Configurations/FeatureDefines.xcconfig
+++ b/Source/WebCore/Configurations/FeatureDefines.xcconfig
@@ -35,12 +35,7 @@
 ENABLE_ACCELERATED_2D_CANVAS = ;
 ENABLE_ACCELERATED_OVERFLOW_SCROLLING[sdk=iphone*] = ENABLE_ACCELERATED_OVERFLOW_SCROLLING;
 ENABLE_ATTACHMENT_ELEMENT = ENABLE_ATTACHMENT_ELEMENT;
-ENABLE_AVF_CAPTIONS[sdk=iphone*] = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS[sdk=macosx*] = $(ENABLE_AVF_CAPTIONS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_AVF_CAPTIONS_macosx_1090 = ;
-ENABLE_AVF_CAPTIONS_macosx_101000 = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS_macosx_101100 = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS_macosx_101200 = ENABLE_AVF_CAPTIONS;
+ENABLE_AVF_CAPTIONS = ENABLE_AVF_CAPTIONS;
 ENABLE_CACHE_PARTITIONING = ENABLE_CACHE_PARTITIONING;
 ENABLE_CANVAS_PATH = ENABLE_CANVAS_PATH;
 ENABLE_CANVAS_PROXY = ;
@@ -76,12 +71,7 @@
 ENABLE_ENCRYPTED_MEDIA[sdk=macosx*] = ENABLE_ENCRYPTED_MEDIA;
 ENABLE_ENCRYPTED_MEDIA_V2[sdk=macosx*] = ENABLE_ENCRYPTED_MEDIA_V2;
 ENABLE_FETCH_API = ENABLE_FETCH_API;
-ENABLE_FILTERS_LEVEL_2[sdk=iphone*] = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2[sdk=macosx*] = $(ENABLE_FILTERS_LEVEL_2_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_FILTERS_LEVEL_2_macosx_1090 = ;
-ENABLE_FILTERS_LEVEL_2_macosx_101000 = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2_macosx_101100 = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2_macosx_101200 = ENABLE_FILTERS_LEVEL_2;
+ENABLE_FILTERS_LEVEL_2 = ENABLE_FILTERS_LEVEL_2;
 ENABLE_FONT_LOAD_EVENTS = ;
 ENABLE_FULLSCREEN_API[sdk=macosx*] = ENABLE_FULLSCREEN_API;
 ENABLE_GAMEPAD[sdk=macosx*] = ENABLE_GAMEPAD;
@@ -89,11 +79,7 @@
 ENABLE_GEOLOCATION = ENABLE_GEOLOCATION;
 ENABLE_HIDDEN_PAGE_DOM_TIMER_THROTTLING[sdk=macosx*] = ENABLE_HIDDEN_PAGE_DOM_TIMER_THROTTLING;
 ENABLE_ICONDATABASE[sdk=macosx*] = ENABLE_ICONDATABASE;
-ENABLE_SERVICE_CONTROLS[sdk=macosx*] = $(ENABLE_SERVICE_CONTROLS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_SERVICE_CONTROLS_macosx_1090 = ;
-ENABLE_SERVICE_CONTROLS_macosx_101000 = ENABLE_SERVICE_CONTROLS;
-ENABLE_SERVICE_CONTROLS_macosx_101100 = ENABLE_SERVICE_CONTROLS;
-ENABLE_SERVICE_CONTROLS_macosx_101200 = ENABLE_SERVICE_CONTROLS;
+ENABLE_SERVICE_CONTROLS[sdk=macosx*] = ENABLE_SERVICE_CONTROLS;
 ENABLE_INDEXED_DATABASE = ENABLE_INDEXED_DATABASE;
 ENABLE_INDEXED_DATABASE_IN_WORKERS = ;
 ENABLE_INDIE_UI = ENABLE_INDIE_UI;
@@ -106,16 +92,10 @@
 ENABLE_INPUT_TYPE_TIME[sdk=iphone*] = ENABLE_INPUT_TYPE_TIME;
 ENABLE_INPUT_TYPE_WEEK[sdk=iphone*] = ENABLE_INPUT_TYPE_WEEK;
 
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS[sdk=iphone*] = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS[sdk=macosx*] = $(ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_1090 = ;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101000 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101100 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101200 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
+ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
 
 ENABLE_WIRELESS_PLAYBACK_TARGET[sdk=iphone*] = ENABLE_WIRELESS_PLAYBACK_TARGET;
 ENABLE_WIRELESS_PLAYBACK_TARGET[sdk=macosx*] = $(ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_1090 = ;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101000 = ;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101100 = ENABLE_WIRELESS_PLAYBACK_TARGET;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101200 = ENABLE_WIRELESS_PLAYBACK_TARGET;
@@ -128,7 +108,6 @@
 
 ENABLE_MAC_GESTURE_EVENTS = ;
 ENABLE_MAC_GESTURE_EVENTS[sdk=macosx*] = $(ENABLE_MAC_GESTURE_EVENTS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR)_WITH_INTERNAL_SDK_$(USE_INTERNAL_SDK));
-ENABLE_MAC_GESTURE_EVENTS_macosx_1090_WITH_INTERNAL_SDK_YES = ;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101000_WITH_INTERNAL_SDK_YES = ;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101100_WITH_INTERNAL_SDK_YES = ENABLE_MAC_GESTURE_EVENTS;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101200_WITH_INTERNAL_SDK_YES = ENABLE_MAC_GESTURE_EVENTS;
@@ -148,11 +127,7 @@
 ENABLE_MEDIA_CONTROLS_SCRIPT = ENABLE_MEDIA_CONTROLS_SCRIPT;
 ENABLE_MEDIA_SESSION = ;
 
-ENABLE_MEDIA_SOURCE[sdk=macosx*] = $(ENABLE_MEDIA_SOURCE_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_MEDIA_SOURCE_macosx_1090 = ;
-ENABLE_MEDIA_SOURCE_macosx_101000 = ENABLE_MEDIA_SOURCE;
-ENABLE_MEDIA_SOURCE_macosx_101100 = ENABLE_MEDIA_SOURCE;
-ENABLE_MEDIA_SOURCE_macosx_101200 = ENABLE_MEDIA_SOURCE;
+ENABLE_MEDIA_SOURCE[sdk=macosx*] = ENABLE_MEDIA_SOURCE;
 
 ENABLE_MEDIA_STATISTICS = ;
 ENABLE_MEDIA_STREAM = ENABLE_MEDIA_STREAM;
@@ -170,12 +145,7 @@
 ENABLE_QUOTA = ;
 ENABLE_REQUEST_ANIMATION_FRAME = ENABLE_REQUEST_ANIMATION_FRAME;
 ENABLE_REQUEST_AUTOCOMPLETE = ;
-ENABLE_REMOTE_INSPECTOR[sdk=iphone*] = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR[sdk=macosx*] = $(ENABLE_REMOTE_INSPECTOR_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_REMOTE_INSPECTOR_macosx_1090 = ;
-ENABLE_REMOTE_INSPECTOR_macosx_101000 = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR_macosx_101100 = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR_macosx_101200 = ENABLE_REMOTE_INSPECTOR;
+ENABLE_REMOTE_INSPECTOR = ENABLE_REMOTE_INSPECTOR;
 ENABLE_RESOLUTION_MEDIA_QUERY = ;
 ENABLE_RUBBER_BANDING[sdk=macosx*] = ENABLE_RUBBER_BANDING;
 ENABLE_CSS_SCROLL_SNAP = ENABLE_CSS_SCROLL_SNAP;
@@ -185,12 +155,7 @@
 ENABLE_SVG_FONTS = ENABLE_SVG_FONTS;
 ENABLE_SVG_OTF_CONVERTER = ENABLE_SVG_OTF_CONVERTER;
 
-ENABLE_TELEPHONE_NUMBER_DETECTION[sdk=iphone*] = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION[sdk=macosx*] = $(ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_1090 = ;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101000 = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101100 = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101200 = ENABLE_TELEPHONE_NUMBER_DETECTION;
+ENABLE_TELEPHONE_NUMBER_DETECTION = ENABLE_TELEPHONE_NUMBER_DETECTION;
 
 ENABLE_TEMPLATE_ELEMENT = ENABLE_TEMPLATE_ELEMENT;
 ENABLE_TEXT_AUTOSIZING = ;
@@ -219,12 +184,7 @@
 ENABLE_WEB_REPLAY_macosx_Release = ENABLE_WEB_REPLAY;
 ENABLE_WEB_SOCKETS = ENABLE_WEB_SOCKETS;
 
-ENABLE_WEB_TIMING[sdk=iphone*] = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING[sdk=macosx*] = $(ENABLE_WEB_TIMING_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_WEB_TIMING_macosx_1090 = ;
-ENABLE_WEB_TIMING_macosx_101000 = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING_macosx_101100 = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING_macosx_101200 = ENABLE_WEB_TIMING;
+ENABLE_WEB_TIMING = ENABLE_WEB_TIMING;
 
 ENABLE_XSLT = ENABLE_XSLT;
 
diff --git a/Source/WebCore/Configurations/Version.xcconfig b/Source/WebCore/Configurations/Version.xcconfig
index a68c035..4316163 100644
--- a/Source/WebCore/Configurations/Version.xcconfig
+++ b/Source/WebCore/Configurations/Version.xcconfig
@@ -35,7 +35,6 @@
 // The system version prefix is based on the current system version.
 SYSTEM_VERSION_PREFIX[sdk=iphone*] = 8;
 SYSTEM_VERSION_PREFIX = $(SYSTEM_VERSION_PREFIX_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-SYSTEM_VERSION_PREFIX_macosx_1090 = 9;
 SYSTEM_VERSION_PREFIX_macosx_101000 = 10;
 SYSTEM_VERSION_PREFIX_macosx_101100 = 11;
 SYSTEM_VERSION_PREFIX_macosx_101200 = 12;
diff --git a/Source/WebCore/accessibility/mac/WebAccessibilityObjectWrapperMac.mm b/Source/WebCore/accessibility/mac/WebAccessibilityObjectWrapperMac.mm
index 86d0f0e..9d11b34 100644
--- a/Source/WebCore/accessibility/mac/WebAccessibilityObjectWrapperMac.mm
+++ b/Source/WebCore/accessibility/mac/WebAccessibilityObjectWrapperMac.mm
@@ -3467,7 +3467,7 @@
 
 - (void)accessibilitySetValue:(id)value forAttribute:(NSString*)attributeName
 {
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     // In case anything we do by changing values causes an alert or other modal
     // behaviors, we need to return now, so that VoiceOver doesn't hang indefinitely.
     dispatch_async(dispatch_get_main_queue(), ^{
diff --git a/Source/WebCore/editing/mac/DictionaryLookup.h b/Source/WebCore/editing/mac/DictionaryLookup.h
index 11ada16..e165bd3 100644
--- a/Source/WebCore/editing/mac/DictionaryLookup.h
+++ b/Source/WebCore/editing/mac/DictionaryLookup.h
@@ -37,7 +37,7 @@
 OBJC_CLASS PDFSelection;
 
 // This file is included in Internals.cpp, so we can't use ObjC outright.
-#if defined(__OBJC__) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if defined(__OBJC__)
 #include "NSImmediateActionGestureRecognizerSPI.h"
 #define PlatformAnimationController id<NSImmediateActionAnimationController>
 #else
diff --git a/Source/WebCore/editing/mac/DictionaryLookup.mm b/Source/WebCore/editing/mac/DictionaryLookup.mm
index 01760ab..e19d12c 100644
--- a/Source/WebCore/editing/mac/DictionaryLookup.mm
+++ b/Source/WebCore/editing/mac/DictionaryLookup.mm
@@ -223,13 +223,9 @@
         if ([getLULookupDefinitionModuleClass() respondsToSelector:@selector(showDefinitionForTerm:relativeToRect:ofView:options:)]) {
             FloatRect firstTextRectInViewCoordinates = textIndicator.get().textRectsInBoundingRectCoordinates()[0];
             firstTextRectInViewCoordinates.moveBy(textIndicator.get().textBoundingRectInRootViewCoordinates().location());
-            if (createAnimationController) {
-#if  __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+            if (createAnimationController)
                 return [getLULookupDefinitionModuleClass() lookupAnimationControllerForTerm:dictionaryPopupInfo.attributedString.get() relativeToRect:firstTextRectInViewCoordinates ofView:view options:mutableOptions.get()];
-#else
-                return nil;
-#endif
-            }
+
             [getLULookupDefinitionModuleClass() showDefinitionForTerm:dictionaryPopupInfo.attributedString.get() relativeToRect:firstTextRectInViewCoordinates ofView:view options:mutableOptions.get()];
             return nil;
         }
@@ -241,13 +237,8 @@
     textBaselineOrigin = [view convertPoint:textBaselineOrigin toView:nil];
     textBaselineOrigin = [view.window convertRectToScreen:NSMakeRect(textBaselineOrigin.x, textBaselineOrigin.y, 0, 0)].origin;
 
-    if (createAnimationController) {
-#if  __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+    if (createAnimationController)
         return [getLULookupDefinitionModuleClass() lookupAnimationControllerForTerm:dictionaryPopupInfo.attributedString.get() atLocation:textBaselineOrigin options:mutableOptions.get()];
-#else
-        return nil;
-#endif
-    }
 
     [getLULookupDefinitionModuleClass() showDefinitionForTerm:dictionaryPopupInfo.attributedString.get() atLocation:textBaselineOrigin options:mutableOptions.get()];
     return nil;
diff --git a/Source/WebCore/html/canvas/WebGLDrawBuffers.cpp b/Source/WebCore/html/canvas/WebGLDrawBuffers.cpp
index e8c209f..7bc72a6 100644
--- a/Source/WebCore/html/canvas/WebGLDrawBuffers.cpp
+++ b/Source/WebCore/html/canvas/WebGLDrawBuffers.cpp
@@ -46,15 +46,6 @@
     return WebGLExtension::WebGLDrawBuffersName;
 }
 
-#if (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED < 101000)
-
-bool WebGLDrawBuffers::supported(WebGLRenderingContextBase*)
-{
-    return false;
-}
-
-#else
-
 bool WebGLDrawBuffers::supported(WebGLRenderingContextBase* context)
 {
     Extensions3D* extensions = context->graphicsContext3D()->getExtensions();
@@ -62,8 +53,6 @@
         && satisfiesWebGLRequirements(context);
 }
 
-#endif
-
 void WebGLDrawBuffers::drawBuffersWEBGL(const Vector<GC3Denum>& buffers)
 {
     if (m_context->isContextLost())
diff --git a/Source/WebCore/loader/DocumentLoader.cpp b/Source/WebCore/loader/DocumentLoader.cpp
index b2ed5de..7937830 100644
--- a/Source/WebCore/loader/DocumentLoader.cpp
+++ b/Source/WebCore/loader/DocumentLoader.cpp
@@ -97,7 +97,6 @@
         loader->setDefersLoading(defers);
 }
 
-#if !PLATFORM(MAC) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 static bool areAllLoadersPageCacheAcceptable(const ResourceLoaderMap& loaders)
 {
     Vector<RefPtr<ResourceLoader>> loadersCopy;
@@ -117,7 +116,6 @@
     }
     return true;
 }
-#endif
 
 DocumentLoader::DocumentLoader(const ResourceRequest& req, const SubstituteData& substituteData)
     : m_deferMainResourceDataLoad(true)
@@ -287,11 +285,8 @@
     // loading but there are subresource loads during cancellation. This must be done before the
     // frame->stopLoading() call, which may evict the CachedResources, which we rely on to check
     // the type of the resource loads.
-#if !PLATFORM(MAC) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-    // Disabled on Mavericks because it seems to cause issues (rdar://problem/22521514).
     if (loading && m_committed && !mainResourceLoader() && !m_subresourceLoaders.isEmpty())
         m_subresourceLoadersArePageCacheAcceptable = areAllLoadersPageCacheAcceptable(m_subresourceLoaders);
-#endif
 
     if (m_committed) {
         // Attempt to stop the frame if the document loader is loading, or if it is done loading but
diff --git a/Source/WebCore/loader/cache/CachedFont.cpp b/Source/WebCore/loader/cache/CachedFont.cpp
index 7b9c1f5..54a8e1b 100644
--- a/Source/WebCore/loader/cache/CachedFont.cpp
+++ b/Source/WebCore/loader/cache/CachedFont.cpp
@@ -102,7 +102,7 @@
     if (!m_fontCustomPlatformData && !errorOccurred() && !isLoading() && data) {
         RefPtr<SharedBuffer> buffer(data);
 
-#if (!PLATFORM(MAC) || __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090) && !PLATFORM(IOS)
+#if !PLATFORM(COCOA)
         if (isWOFF(buffer.get())) {
             Vector<char> convertedFont;
             if (!convertWOFFToSfnt(buffer.get(), convertedFont))
diff --git a/Source/WebCore/loader/cocoa/DiskCacheMonitorCocoa.h b/Source/WebCore/loader/cocoa/DiskCacheMonitorCocoa.h
index ab9a0fd..e4c23fe 100644
--- a/Source/WebCore/loader/cocoa/DiskCacheMonitorCocoa.h
+++ b/Source/WebCore/loader/cocoa/DiskCacheMonitorCocoa.h
@@ -55,19 +55,6 @@
     SessionID m_sessionID;
 };
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED < 1090
-
-inline void DiskCacheMonitor::monitorFileBackingStoreCreation(const ResourceRequest&, SessionID, CFCachedURLResponseRef)
-{
-}
-
-inline PassRefPtr<SharedBuffer> DiskCacheMonitor::tryGetFileBackedSharedBufferFromCFURLCachedResponse(CFCachedURLResponseRef)
-{
-    return nullptr;
-}
-
-#endif
-
 } // namespace WebKit
 
 #endif // DiskCacheMonitorCocoa_h
diff --git a/Source/WebCore/page/cocoa/SettingsCocoa.mm b/Source/WebCore/page/cocoa/SettingsCocoa.mm
index 6dd5dc0..e94bc19 100644
--- a/Source/WebCore/page/cocoa/SettingsCocoa.mm
+++ b/Source/WebCore/page/cocoa/SettingsCocoa.mm
@@ -41,20 +41,12 @@
 
 static inline const char* sansSerifTraditionalHanFontFamily()
 {
-#if (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000) || PLATFORM(IOS)
     return "PingFang TC";
-#else
-    return "Heiti TC";
-#endif
 }
 
 static inline const char* sansSerifSimplifiedHanFontFamily()
 {
-#if (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000) || PLATFORM(IOS)
     return "PingFang SC";
-#else
-    return "Heiti SC";
-#endif
 }
 
 #if PLATFORM(MAC)
diff --git a/Source/WebCore/platform/Scrollbar.cpp b/Source/WebCore/platform/Scrollbar.cpp
index c498457..8d8eff8 100644
--- a/Source/WebCore/platform/Scrollbar.cpp
+++ b/Source/WebCore/platform/Scrollbar.cpp
@@ -478,7 +478,7 @@
 {
     // It's unfortunate that this needs to be done with an ifdef. Ideally there would be a way to feature-detect
     // the necessary support within AppKit.
-#if ENABLE(ASYNC_SCROLLING) && PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if ENABLE(ASYNC_SCROLLING) && PLATFORM(MAC)
     return !m_scrollableArea.forceUpdateScrollbarsOnMainThreadForPerformanceTesting()
         && (m_scrollableArea.hasLayerForVerticalScrollbar() || m_scrollableArea.hasLayerForHorizontalScrollbar())
         && m_scrollableArea.usesAsyncScrolling();
diff --git a/Source/WebCore/platform/cocoa/MemoryPressureHandlerCocoa.mm b/Source/WebCore/platform/cocoa/MemoryPressureHandlerCocoa.mm
index 6d0d0e0..03a264b 100644
--- a/Source/WebCore/platform/cocoa/MemoryPressureHandlerCocoa.mm
+++ b/Source/WebCore/platform/cocoa/MemoryPressureHandlerCocoa.mm
@@ -68,16 +68,12 @@
     }
 #endif
 
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if (critical == Critical::Yes && !isUnderMemoryPressure()) {
         // libcache listens to OS memory notifications, but for process suspension
         // or memory pressure simulation, we need to prod it manually:
         ReliefLogger log("Purging libcache caches");
         cache_simulate_memory_warning_event(DISPATCH_MEMORYPRESSURE_CRITICAL);
     }
-#else
-    UNUSED_PARAM(critical);
-#endif
 }
 
 static dispatch_source_t _cache_event_source = 0;
diff --git a/Source/WebCore/platform/cocoa/NetworkExtensionContentFilter.h b/Source/WebCore/platform/cocoa/NetworkExtensionContentFilter.h
index bfeff5b..1c44a1b 100644
--- a/Source/WebCore/platform/cocoa/NetworkExtensionContentFilter.h
+++ b/Source/WebCore/platform/cocoa/NetworkExtensionContentFilter.h
@@ -32,7 +32,7 @@
 #include <wtf/OSObjectPtr.h>
 #include <wtf/RetainPtr.h>
 
-#define HAVE_NETWORK_EXTENSION PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000 && CPU(X86_64))
+#define HAVE_NETWORK_EXTENSION PLATFORM(IOS) || (PLATFORM(MAC) && CPU(X86_64))
 
 enum NEFilterSourceStatus : NSInteger;
 
diff --git a/Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm b/Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm
index 980e431..1863cd2 100644
--- a/Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm
+++ b/Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm
@@ -682,7 +682,7 @@
         if (!m_videoLayer)
             createAVPlayerLayer();
 
-#if USE(VIDEOTOOLBOX) && (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#if USE(VIDEOTOOLBOX)
         if (!m_videoOutput)
             createVideoOutput();
 #endif
@@ -2216,7 +2216,7 @@
     if (!m_avPlayerItem || m_videoOutput)
         return;
 
-#if USE(VIDEOTOOLBOX) && (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#if USE(VIDEOTOOLBOX)
     NSDictionary* attributes = nil;
 #else
     NSDictionary* attributes = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA], kCVPixelBufferPixelFormatTypeKey,
@@ -2229,10 +2229,6 @@
 
     [m_avPlayerItem.get() addOutput:m_videoOutput.get()];
 
-#if defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-    waitForVideoOutputMediaDataWillChange();
-#endif
-
     LOG(Media, "MediaPlayerPrivateAVFoundationObjC::createVideoOutput(%p) - returning %p", this, m_videoOutput.get());
 }
 
@@ -2353,10 +2349,8 @@
 
 void MediaPlayerPrivateAVFoundationObjC::paintWithVideoOutput(GraphicsContext& context, const FloatRect& outputRect)
 {
-#if (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
     if (m_videoOutput && !m_lastImage && !videoOutputHasAvailableFrame())
         waitForVideoOutputMediaDataWillChange();
-#endif
 
     updateLastImage();
 
diff --git a/Source/WebCore/platform/graphics/cg/ImageSourceCG.cpp b/Source/WebCore/platform/graphics/cg/ImageSourceCG.cpp
index 953faea..3189ca7 100644
--- a/Source/WebCore/platform/graphics/cg/ImageSourceCG.cpp
+++ b/Source/WebCore/platform/graphics/cg/ImageSourceCG.cpp
@@ -368,7 +368,7 @@
     if (!imageUTI)
         return image.leakRef();
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     if (CFEqual(imageUTI, kUTTypeGIF)) {
         CGImageSetCachingFlags(image.get(), kCGImageCachingTransient);
         return image.leakRef();
diff --git a/Source/WebCore/platform/graphics/cocoa/FontCacheCoreText.cpp b/Source/WebCore/platform/graphics/cocoa/FontCacheCoreText.cpp
index 9e3f2f8..0066946 100644
--- a/Source/WebCore/platform/graphics/cocoa/FontCacheCoreText.cpp
+++ b/Source/WebCore/platform/graphics/cocoa/FontCacheCoreText.cpp
@@ -133,7 +133,6 @@
 
 static inline void appendOpenTypeFeature(CFMutableArrayRef features, const FontFeature& feature)
 {
-#if (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000) || PLATFORM(IOS)
     RetainPtr<CFStringRef> featureKey = adoptCF(CFStringCreateWithBytes(kCFAllocatorDefault, reinterpret_cast<const UInt8*>(feature.tag().data()), feature.tag().size() * sizeof(FontFeatureTag::value_type), kCFStringEncodingASCII, false));
     int rawFeatureValue = feature.value();
     RetainPtr<CFNumberRef> featureValue = adoptCF(CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &rawFeatureValue));
@@ -141,10 +140,6 @@
     CFTypeRef featureDictionaryValues[] = { featureKey.get(), featureValue.get() };
     RetainPtr<CFDictionaryRef> featureDictionary = adoptCF(CFDictionaryCreate(kCFAllocatorDefault, featureDictionaryKeys, featureDictionaryValues, WTF_ARRAY_LENGTH(featureDictionaryValues), &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks));
     CFArrayAppendValue(features, featureDictionary.get());
-#else
-    UNUSED_PARAM(features);
-    UNUSED_PARAM(feature);
-#endif
 }
 
 typedef HashMap<FontFeatureTag, int, FontFeatureTagHash, FontFeatureTagHashTraits> FeaturesMap;
diff --git a/Source/WebCore/platform/graphics/cocoa/FontCascadeCocoa.mm b/Source/WebCore/platform/graphics/cocoa/FontCascadeCocoa.mm
index 594d76a..f9cbba7 100644
--- a/Source/WebCore/platform/graphics/cocoa/FontCascadeCocoa.mm
+++ b/Source/WebCore/platform/graphics/cocoa/FontCascadeCocoa.mm
@@ -591,17 +591,8 @@
 
 bool FontCascade::primaryFontIsSystemFont() const
 {
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED > 1090
     const auto& fontData = primaryFont();
     return !fontData.isSVGFont() && CTFontDescriptorIsSystemUIFont(adoptCF(CTFontCopyFontDescriptor(fontData.platformData().ctFont())).get());
-#else
-    const String& firstFamily = this->firstFamily();
-    return equalIgnoringASCIICase(firstFamily, "-webkit-system-font")
-        || equalIgnoringASCIICase(firstFamily, "-apple-system-font")
-        || equalIgnoringASCIICase(firstFamily, "-apple-system")
-        || equalIgnoringASCIICase(firstFamily, "-apple-menu")
-        || equalIgnoringASCIICase(firstFamily, "-apple-status-bar");
-#endif
 }
 
 void FontCascade::adjustSelectionRectForComplexText(const TextRun& run, LayoutRect& selectionRect, int from, int to) const
diff --git a/Source/WebCore/platform/graphics/mac/GraphicsContext3DMac.mm b/Source/WebCore/platform/graphics/mac/GraphicsContext3DMac.mm
index 544ebf6..4b761de 100644
--- a/Source/WebCore/platform/graphics/mac/GraphicsContext3DMac.mm
+++ b/Source/WebCore/platform/graphics/mac/GraphicsContext3DMac.mm
@@ -63,15 +63,11 @@
 
 namespace WebCore {
 
-#define USE_GPU_STATUS_CHECK ((PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000) || PLATFORM(IOS))
-
 const int maxActiveContexts = 64;
 int GraphicsContext3D::numActiveContexts = 0;
-#if USE_GPU_STATUS_CHECK
 const int GPUStatusCheckThreshold = 5;
 int GraphicsContext3D::GPUCheckCounter = 0;
-#endif
-    
+
 // FIXME: This class is currently empty on Mac, but will get populated as 
 // the restructuring in https://bugs.webkit.org/show_bug.cgi?id=66903 is done
 class GraphicsContext3DPrivate {
@@ -205,14 +201,12 @@
         return;
 
     CGLError err = CGLCreateContext(pixelFormatObj, 0, &m_contextObj);
-#if USE_GPU_STATUS_CHECK
     GLint abortOnBlacklist = 0;
 #if PLATFORM(MAC)
     CGLSetParameter(m_contextObj, kCGLCPAbortOnGPURestartStatusBlacklisted, &abortOnBlacklist);
 #elif PLATFORM(IOS)
     CGLSetParameter(m_contextObj, kEAGLCPAbortOnGPURestartStatusBlacklisted, &abortOnBlacklist);
 #endif
-#endif
 
     CGLDestroyPixelFormat(pixelFormatObj);
     
@@ -373,7 +367,6 @@
 
 void GraphicsContext3D::checkGPUStatusIfNecessary()
 {
-#if USE_GPU_STATUS_CHECK
     bool needsCheck = !GPUCheckCounter;
     GPUCheckCounter = (GPUCheckCounter + 1) % GPUStatusCheckThreshold;
 
@@ -397,7 +390,6 @@
         [EAGLContext setCurrentContext:0];
     }
 #endif
-#endif
 }
 
 #if PLATFORM(IOS)
diff --git a/Source/WebCore/platform/mac/NSScrollerImpDetails.h b/Source/WebCore/platform/mac/NSScrollerImpDetails.h
index 992a645..f9462fb 100644
--- a/Source/WebCore/platform/mac/NSScrollerImpDetails.h
+++ b/Source/WebCore/platform/mac/NSScrollerImpDetails.h
@@ -63,9 +63,7 @@
 - (void)mouseEnteredScroller;
 - (void)mouseExitedScroller;
 - (void)setTracking:(BOOL)tracking;
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 - (void)setNeedsDisplay:(BOOL)flag;
-#endif
 @end
 
 @interface NSObject (ScrollbarPainterController)
diff --git a/Source/WebCore/platform/mac/ScrollAnimatorMac.mm b/Source/WebCore/platform/mac/ScrollAnimatorMac.mm
index bbec869..98dded7 100644
--- a/Source/WebCore/platform/mac/ScrollAnimatorMac.mm
+++ b/Source/WebCore/platform/mac/ScrollAnimatorMac.mm
@@ -1025,17 +1025,11 @@
     [m_scrollbarPainterController setHorizontalScrollerImp:nil];
 }
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 void ScrollAnimatorMac::invalidateScrollbarPartLayers(Scrollbar* scrollbar)
 {
     ScrollbarPainter painter = scrollbarPainterForScrollbar(*scrollbar);
     [painter setNeedsDisplay:YES];
 }
-#else
-void ScrollAnimatorMac::invalidateScrollbarPartLayers(Scrollbar*)
-{
-}
-#endif
 
 void ScrollAnimatorMac::verticalScrollbarLayerDidChange()
 {
diff --git a/Source/WebCore/platform/mac/ScrollViewMac.mm b/Source/WebCore/platform/mac/ScrollViewMac.mm
index 1fd9ef1..24c6ab9 100644
--- a/Source/WebCore/platform/mac/ScrollViewMac.mm
+++ b/Source/WebCore/platform/mac/ScrollViewMac.mm
@@ -38,12 +38,6 @@
 - (NSEdgeInsets)contentInsets;
 @end
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-@interface NSScrollView (WebDetails)
-@property BOOL automaticallyAdjustsContentInsets;
-@end
-#endif
-
 @interface NSWindow (WebWindowDetails)
 - (BOOL)_needsToResetDragMargins;
 - (void)_setNeedsToResetDragMargins:(BOOL)needs;
@@ -117,9 +111,7 @@
 float ScrollView::platformTopContentInset() const
 {
     BEGIN_BLOCK_OBJC_EXCEPTIONS;
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     return scrollView().contentInsets.top;
-#endif
     END_BLOCK_OBJC_EXCEPTIONS;
 
     return 0;
@@ -128,7 +120,6 @@
 void ScrollView::platformSetTopContentInset(float topContentInset)
 {
     BEGIN_BLOCK_OBJC_EXCEPTIONS;
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if (topContentInset)
         scrollView().automaticallyAdjustsContentInsets = NO;
     else
@@ -137,9 +128,6 @@
     NSEdgeInsets contentInsets = scrollView().contentInsets;
     contentInsets.top = topContentInset;
     scrollView().contentInsets = contentInsets;
-#else
-    UNUSED_PARAM(topContentInset);
-#endif
     END_BLOCK_OBJC_EXCEPTIONS;
 }
 
@@ -148,10 +136,8 @@
     BEGIN_BLOCK_OBJC_EXCEPTIONS;
     IntRect visibleContentRect = platformVisibleContentRectIncludingObscuredArea(includeScrollbars);
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     visibleContentRect.move(scrollView().contentInsets.left, scrollView().contentInsets.top);
     visibleContentRect.contract(scrollView().contentInsets.left + scrollView().contentInsets.right, scrollView().contentInsets.top + scrollView().contentInsets.bottom);
-#endif
 
     return visibleContentRect;
     END_BLOCK_OBJC_EXCEPTIONS;
@@ -209,12 +195,10 @@
     NSPoint floatPoint = scrollPoint;
     NSPoint tempPoint = { std::max(-[scrollView() scrollOrigin].x, floatPoint.x), std::max(-[scrollView() scrollOrigin].y, floatPoint.y) };  // Don't use NSMakePoint to work around 4213314.
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     // AppKit has the inset factored into all of its scroll positions. In WebCore, we use positions that ignore
     // the insets so that they are equivalent whether or not there is an inset.
     tempPoint.x = tempPoint.x - scrollView().contentInsets.left;
     tempPoint.y = tempPoint.y - scrollView().contentInsets.top;
-#endif
 
     [documentView() scrollPoint:tempPoint];
     END_BLOCK_OBJC_EXCEPTIONS;
diff --git a/Source/WebCore/platform/mac/ScrollbarThemeMac.mm b/Source/WebCore/platform/mac/ScrollbarThemeMac.mm
index 9cfd048..b031af2 100644
--- a/Source/WebCore/platform/mac/ScrollbarThemeMac.mm
+++ b/Source/WebCore/platform/mac/ScrollbarThemeMac.mm
@@ -483,7 +483,7 @@
     [painter setEnabled:scrollbar.enabled()];
     [painter setBoundsSize:scrollbar.frameRect().size()];
     [painter setDoubleValue:value];
-#if ENABLE(ASYNC_SCROLLING) && PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if ENABLE(ASYNC_SCROLLING) && PLATFORM(MAC)
     [painter setPresentationValue:value];
 #endif
     [painter setKnobProportion:proportion];
diff --git a/Source/WebCore/platform/mac/ThemeMac.mm b/Source/WebCore/platform/mac/ThemeMac.mm
index d3089d9..d26193b 100644
--- a/Source/WebCore/platform/mac/ThemeMac.mm
+++ b/Source/WebCore/platform/mac/ThemeMac.mm
@@ -186,10 +186,6 @@
 
 static void updateStates(NSCell* cell, const ControlStates& controlStates, bool useAnimation = false)
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-    UNUSED_PARAM(useAnimation);
-#endif
-
     // The animated state cause this thread to start and stop repeatedly on CoreAnimation synchronize calls.
     // This short burts of activity in between are not long enough for VoiceOver to retrieve accessibility attributes and makes the process appear unresponsive.
     if (AXObjectCache::accessibilityEnhancedUserInterfaceEnabled())
@@ -203,11 +199,7 @@
     bool oldPressed = [cell isHighlighted];
     bool pressed = states & ControlStates::PressedState;
     if (pressed != oldPressed) {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         [(NSButtonCell*)cell _setHighlighted:pressed animated:useAnimation];
-#else
-        [cell setHighlighted:pressed];
-#endif
     }
     
     // Enabled state
@@ -223,11 +215,7 @@
     bool oldChecked = [cell state] == NSOnState;
     if (oldIndeterminate != indeterminate || checked != oldChecked) {
         NSCellStateValue newState = indeterminate ? NSMixedState : (checked ? NSOnState : NSOffState);
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         [(NSButtonCell*)cell _setState:newState animated:useAnimation];
-#else
-        [cell setState:newState];
-#endif
     }
 
     // Window inactive state does not need to be checked explicitly, since we paint parented to 
@@ -419,17 +407,12 @@
 
     LocalCurrentGraphicsContext localContext(context);
 
-    bool useUnparentedView = false;
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-    useUnparentedView = true;
-#endif
-    NSView *view = ThemeMac::ensuredView(scrollView, controlStates, useUnparentedView);
+    NSView *view = ThemeMac::ensuredView(scrollView, controlStates, true /* useUnparentedView */);
 
     bool needsRepaint = false;
     bool useImageBuffer = pageScaleFactor != 1.0f || zoomFactor != 1.0f;
     bool isCellFocused = controlStates.states() & ControlStates::FocusState;
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if ([toggleButtonCell _stateAnimationRunning]) {
         context.translate(inflatedRect.x(), inflatedRect.y());
         context.scale(FloatSize(1, -1));
@@ -440,15 +423,10 @@
             needsRepaint = ThemeMac::drawCellOrFocusRingWithViewIntoContext(toggleButtonCell.get(), context, inflatedRect, view, false, true, useImageBuffer, deviceScaleFactor);
     } else
         needsRepaint = ThemeMac::drawCellOrFocusRingWithViewIntoContext(toggleButtonCell.get(), context, inflatedRect, view, true, isCellFocused, useImageBuffer, deviceScaleFactor);
-#else
-    needsRepaint = ThemeMac::drawCellOrFocusRingWithViewIntoContext(toggleButtonCell.get(), context, inflatedRect, view, true, isCellFocused, useImageBuffer, deviceScaleFactor);
-#endif
 
     [toggleButtonCell setControlView:nil];
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     needsRepaint |= [toggleButtonCell _stateAnimationRunning];
-#endif
     controlStates.setNeedsRepaint(needsRepaint);
     if (needsRepaint)
         controlStates.setPlatformControl(toggleButtonCell.get());
@@ -561,12 +539,9 @@
 
     bool useImageBuffer = pageScaleFactor != 1.0f || zoomFactor != 1.0f;
     bool needsRepaint = ThemeMac::drawCellOrFocusRingWithViewIntoContext(buttonCell, context, inflatedRect, view, true, states & ControlStates::FocusState, useImageBuffer, deviceScaleFactor);
-    if (states & ControlStates::DefaultState) {
+    if (states & ControlStates::DefaultState)
         [window setDefaultButtonCell:buttonCell];
-#if __MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-        wkAdvanceDefaultButtonPulseAnimation(buttonCell);
-#endif
-    } else if ([previousDefaultButtonCell isEqual:buttonCell])
+    else if ([previousDefaultButtonCell isEqual:buttonCell])
         [window setDefaultButtonCell:nil];
     
     controlStates.setNeedsRepaint(needsRepaint);
diff --git a/Source/WebCore/platform/mac/WebCoreFullScreenPlaceholderView.h b/Source/WebCore/platform/mac/WebCoreFullScreenPlaceholderView.h
index 770f645..59f0d39 100644
--- a/Source/WebCore/platform/mac/WebCoreFullScreenPlaceholderView.h
+++ b/Source/WebCore/platform/mac/WebCoreFullScreenPlaceholderView.h
@@ -31,12 +31,8 @@
 #import <wtf/RetainPtr.h>
 
 WEBCORE_EXPORT @interface WebCoreFullScreenPlaceholderView : NSView {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     RetainPtr<NSVisualEffectView> _effectView;
     RetainPtr<NSTextField> _exitWarning;
-#else
-    RetainPtr<NSView> _exitWarning;
-#endif
     NSObject* _target;
     SEL _action;
 }
diff --git a/Source/WebCore/platform/mac/WebCoreFullScreenPlaceholderView.mm b/Source/WebCore/platform/mac/WebCoreFullScreenPlaceholderView.mm
index 4c6494a..515d751 100644
--- a/Source/WebCore/platform/mac/WebCoreFullScreenPlaceholderView.mm
+++ b/Source/WebCore/platform/mac/WebCoreFullScreenPlaceholderView.mm
@@ -45,7 +45,6 @@
     if (!self)
         return nil;
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     self.wantsLayer = YES;
     self.autoresizesSubviews = YES;
     self.layerContentsPlacement = NSViewLayerContentsPlacementScaleProportionallyToFit;
@@ -76,18 +75,6 @@
     warningFrame.origin = NSMakePoint((frameRect.size.width - warningFrame.size.width) / 2, frameRect.size.height / 2);
     _exitWarning.get().frame = warningFrame;
     [_effectView addSubview:_exitWarning.get()];
-#else
-    [self setLayer:[CALayer layer]];
-    [self setLayerContentsRedrawPolicy:NSViewLayerContentsRedrawNever];
-    [self setWantsLayer:YES];
-
-    _exitWarning = adoptNS([[WebCoreFullScreenWarningView alloc] initWithTitle:clickToExitFullScreenText()]);
-    NSRect warningFrame = [_exitWarning.get() frame];
-    warningFrame.origin = NSMakePoint((frameRect.size.width - warningFrame.size.width) / 2, (frameRect.size.height - warningFrame.size.height) / 2);
-    [_exitWarning.get() setFrame:warningFrame];
-    [_exitWarning.get() setHidden:YES];
-    [self addSubview:_exitWarning.get()];
-#endif
 
     return self;
 }
@@ -108,18 +95,7 @@
 
 - (void)setExitWarningVisible:(BOOL)visible
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     [_effectView setHidden:!visible];
-#else
-    [_exitWarning.get() setHidden:!visible];
-    if (visible) {
-        CAFilter* filter = [CAFilter filterWithType:@"colorMonochrome"];
-        [filter setValue:[NSNumber numberWithFloat:-0.2] forKey:@"inputBias"];
-        [filter setValue:[NSNumber numberWithFloat:1] forKey:@"inputAmount"];
-        [[self layer] setFilters:[NSArray arrayWithObject:filter]];
-    } else
-        [[self layer] setFilters:nil];
-#endif
 }
 
 - (void)mouseDown:(NSEvent *)theEvent
diff --git a/Source/WebCore/platform/network/cf/CookieJarCFNet.cpp b/Source/WebCore/platform/network/cf/CookieJarCFNet.cpp
index 947fb3b..e8fdbdd 100644
--- a/Source/WebCore/platform/network/cf/CookieJarCFNet.cpp
+++ b/Source/WebCore/platform/network/cf/CookieJarCFNet.cpp
@@ -42,7 +42,7 @@
 #include <windows.h>
 #endif
 
-#if PLATFORM(WIN) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090)
+#if PLATFORM(WIN)
 enum {
     CFHTTPCookieStorageAcceptPolicyExclusivelyFromMainDocumentDomain = 3
 };
@@ -105,7 +105,7 @@
 {
     bool secure = url.protocolIs("https");
 
-#if PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#if PLATFORM(COCOA)
     return adoptCF(_CFHTTPCookieStorageCopyCookiesForURLWithMainDocumentURL(session.cookieStorage().get(), url.createCFURL().get(), firstParty.createCFURL().get(), secure));
 #else
     // _CFHTTPCookieStorageCopyCookiesForURLWithMainDocumentURL is not available on other platforms.
diff --git a/Source/WebCore/platform/network/cf/ResourceRequest.h b/Source/WebCore/platform/network/cf/ResourceRequest.h
index 8a5ef09..6c9202b 100644
--- a/Source/WebCore/platform/network/cf/ResourceRequest.h
+++ b/Source/WebCore/platform/network/cf/ResourceRequest.h
@@ -151,14 +151,8 @@
 
     inline bool ResourceRequest::resourcePrioritiesEnabled()
     {
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     return true;
-#elif PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-    // See <rdar://problem/16518595>, <rdar://problem/17168793> for issues we had before OS X 10.10.
-    // HTTP Pipelining could be enabled for experiments, but there is no point in doing so on old OS versions,
-    // and that can't work well because of the above issues.
-    ASSERT(!httpPipeliningEnabled());
-    return false;
 #elif PLATFORM(IOS)
     return true;
 #elif PLATFORM(WIN)
diff --git a/Source/WebCore/platform/spi/cf/CFNetworkSPI.h b/Source/WebCore/platform/spi/cf/CFNetworkSPI.h
index eea520a..b8a0c95 100644
--- a/Source/WebCore/platform/spi/cf/CFNetworkSPI.h
+++ b/Source/WebCore/platform/spi/cf/CFNetworkSPI.h
@@ -37,7 +37,7 @@
 #include <CFNetwork/CFURLRequest.h>
 
 // FIXME: Remove the defined(__OBJC__)-guard onnce we fix <rdar://problem/19033610>.
-#if defined(__OBJC__) && (PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#if defined(__OBJC__) && PLATFORM(COCOA)
 // FIXME: As a workaround for <rdar://problem/18337182>, we conditionally enclose the header
 // in an extern "C" linkage block to make it suitable for C++ use.
 #ifdef __cplusplus
@@ -49,7 +49,7 @@
 #ifdef __cplusplus
 }
 #endif
-#endif // defined(__OBJC__) && (PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#endif // defined(__OBJC__) && PLATFORM(COCOA)
 
 #else // PLATFORM(WIN) || USE(APPLE_INTERNAL_SDK)
 
@@ -112,7 +112,7 @@
 @end
 #endif
 
-#if defined(__OBJC__) && (!USE(APPLE_INTERNAL_SDK) || PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090)
+#if defined(__OBJC__) && !USE(APPLE_INTERNAL_SDK)
 enum : NSUInteger {
     NSHTTPCookieAcceptPolicyExclusivelyFromMainDocumentDomain = 3,
 };
@@ -128,7 +128,7 @@
 EXTERN_C Boolean _CFNetworkSetATSContext(CFDataRef);
 #endif
 
-#if PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#if PLATFORM(COCOA)
 EXTERN_C void _CFNetworkResetHSTSHostsSinceDate(CFURLStorageSessionRef, CFDateRef);
 #endif
 
@@ -146,7 +146,7 @@
 @end
 #endif
 
-#if !USE(APPLE_INTERNAL_SDK) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED == 1090)
+#if !USE(APPLE_INTERNAL_SDK)
 @interface NSHTTPCookieStorage ()
 - (void)removeCookiesSinceDate:(NSDate *)date;
 - (id)_initWithCFHTTPCookieStorage:(CFHTTPCookieStorageRef)cfStorage;
diff --git a/Source/WebCore/platform/spi/cocoa/CoreTextSPI.h b/Source/WebCore/platform/spi/cocoa/CoreTextSPI.h
index d6c9bbe..030d2aa 100644
--- a/Source/WebCore/platform/spi/cocoa/CoreTextSPI.h
+++ b/Source/WebCore/platform/spi/cocoa/CoreTextSPI.h
@@ -92,7 +92,7 @@
 CTFontRef CTFontCreateForCSS(CFStringRef name, uint16_t weight, CTFontSymbolicTraits, CGFloat size);
 CTFontRef CTFontCreateForCharactersWithLanguage(CTFontRef currentFont, const UTF16Char *characters, CFIndex length, CFStringRef language, CFIndex *coveredLength);
 
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(COCOA)
 extern const CFStringRef kCTUIFontTextStyleShortHeadline;
 extern const CFStringRef kCTUIFontTextStyleShortBody;
 extern const CFStringRef kCTUIFontTextStyleShortSubhead;
diff --git a/Source/WebCore/platform/spi/cocoa/NSButtonCellSPI.h b/Source/WebCore/platform/spi/cocoa/NSButtonCellSPI.h
index 0df477e..60ab0bb 100644
--- a/Source/WebCore/platform/spi/cocoa/NSButtonCellSPI.h
+++ b/Source/WebCore/platform/spi/cocoa/NSButtonCellSPI.h
@@ -25,8 +25,6 @@
 
 #import <AppKit/NSButtonCell.h>
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 #if USE(APPLE_INTERNAL_SDK)
 
 #import <AppKit/NSButtonCell_Private.h>
@@ -42,5 +40,3 @@
 
 #endif
 
-#endif
-
diff --git a/Source/WebCore/platform/spi/cocoa/NSColorSPI.h b/Source/WebCore/platform/spi/cocoa/NSColorSPI.h
index 6751c08..99ed496 100644
--- a/Source/WebCore/platform/spi/cocoa/NSColorSPI.h
+++ b/Source/WebCore/platform/spi/cocoa/NSColorSPI.h
@@ -25,8 +25,6 @@
 
 #import <AppKit/NSColor.h>
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 #if PLATFORM(MAC) && USE(APPLE_INTERNAL_SDK)
 
 #import <AppKit/NSColor_Private.h>
@@ -46,5 +44,3 @@
 @end
 
 #endif
-
-#endif
diff --git a/Source/WebCore/platform/spi/cocoa/QuartzCoreSPI.h b/Source/WebCore/platform/spi/cocoa/QuartzCoreSPI.h
index 34b2939..26c1bf5 100644
--- a/Source/WebCore/platform/spi/cocoa/QuartzCoreSPI.h
+++ b/Source/WebCore/platform/spi/cocoa/QuartzCoreSPI.h
@@ -70,12 +70,10 @@
 - (uint32_t)createImageSlot:(CGSize)size hasAlpha:(BOOL)flag;
 - (void)deleteSlot:(uint32_t)name;
 - (void)invalidate;
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 - (mach_port_t)createFencePort;
 - (void)setFencePort:(mach_port_t)port;
 - (void)setFencePort:(mach_port_t)port commitHandler:(void(^)(void))block;
-#endif
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101100
+#if PLATFORM(MAC)
 @property BOOL colorMatchUntaggedContent;
 #endif
 @property (readonly) uint32_t contextId;
diff --git a/Source/WebCore/platform/spi/mac/LookupSPI.h b/Source/WebCore/platform/spi/mac/LookupSPI.h
index b2dc3dd..5cae094 100644
--- a/Source/WebCore/platform/spi/mac/LookupSPI.h
+++ b/Source/WebCore/platform/spi/mac/LookupSPI.h
@@ -48,8 +48,6 @@
 
 #endif // !USE(APPLE_INTERNAL_SDK)
 
-#if  __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 @interface LULookupDefinitionModule ()
 
 + (id<NSImmediateActionAnimationController>)lookupAnimationControllerForTerm:(NSAttributedString *)term atLocation:(NSPoint)screenPoint options:(NSDictionary *)options;
@@ -58,8 +56,6 @@
 
 @end
 
-#endif // __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 @interface LULookupDefinitionModule ()
 
 + (void)showDefinitionForTerm:(NSAttributedString *)term relativeToRect:(NSRect)positioningRect ofView:(NSView *)positioningView options:(NSDictionary *)options;
diff --git a/Source/WebCore/platform/spi/mac/NSFontSPI.h b/Source/WebCore/platform/spi/mac/NSFontSPI.h
index 00fa986..d7cc5f7 100644
--- a/Source/WebCore/platform/spi/mac/NSFontSPI.h
+++ b/Source/WebCore/platform/spi/mac/NSFontSPI.h
@@ -38,7 +38,6 @@
 + (NSFont *)systemFontOfSize:(CGFloat)size weight:(CGFloat)weight;
 @end
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 extern const CGFloat NSFontWeightUltraLight;
 extern const CGFloat NSFontWeightThin;
 extern const CGFloat NSFontWeightLight;
@@ -48,7 +47,6 @@
 extern const CGFloat NSFontWeightBold;
 extern const CGFloat NSFontWeightHeavy;
 extern const CGFloat NSFontWeightBlack;
-#endif
 
 #endif
 
diff --git a/Source/WebCore/platform/spi/mac/NSImmediateActionGestureRecognizerSPI.h b/Source/WebCore/platform/spi/mac/NSImmediateActionGestureRecognizerSPI.h
index 0dca331..6af4f29 100644
--- a/Source/WebCore/platform/spi/mac/NSImmediateActionGestureRecognizerSPI.h
+++ b/Source/WebCore/platform/spi/mac/NSImmediateActionGestureRecognizerSPI.h
@@ -25,8 +25,6 @@
 #ifndef NSImmediateActionGestureRecognizerSPI_h
 #define NSImmediateActionGestureRecognizerSPI_h
 
-#if  __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 #import <AppKit/NSGestureRecognizer.h>
 
 // FIXME: This header should include system headers when possible.
@@ -61,6 +59,4 @@
 
 @end
 
-#endif // __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 #endif
diff --git a/Source/WebCore/platform/spi/mac/NSPopoverSPI.h b/Source/WebCore/platform/spi/mac/NSPopoverSPI.h
index 0142465..6329c4e 100644
--- a/Source/WebCore/platform/spi/mac/NSPopoverSPI.h
+++ b/Source/WebCore/platform/spi/mac/NSPopoverSPI.h
@@ -23,8 +23,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#if  __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 #import "NSImmediateActionGestureRecognizerSPI.h"
 
 // FIXME: This header should include system headers when possible.
@@ -46,5 +44,3 @@
 @interface NSPopover (WKDetails)
 @property NSPopoverPositioningOptions positioningOptions;
 @end
-
-#endif // __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
diff --git a/Source/WebCore/platform/spi/mac/NSSharingServicePickerSPI.h b/Source/WebCore/platform/spi/mac/NSSharingServicePickerSPI.h
index 7b226b4..d0ffb1c 100644
--- a/Source/WebCore/platform/spi/mac/NSSharingServicePickerSPI.h
+++ b/Source/WebCore/platform/spi/mac/NSSharingServicePickerSPI.h
@@ -23,8 +23,6 @@
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 #if USE(APPLE_INTERNAL_SDK)
 
 #import <AppKit/NSSharingService_Private.h>
@@ -47,5 +45,3 @@
 @end
 
 #endif
-
-#endif
diff --git a/Source/WebCore/platform/spi/mac/NSSharingServiceSPI.h b/Source/WebCore/platform/spi/mac/NSSharingServiceSPI.h
index ff8b41a..4a172da 100644
--- a/Source/WebCore/platform/spi/mac/NSSharingServiceSPI.h
+++ b/Source/WebCore/platform/spi/mac/NSSharingServiceSPI.h
@@ -23,8 +23,6 @@
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#if  __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 #if USE(APPLE_INTERNAL_SDK)
 
 #import <AppKit/NSSharingService_Private.h>
@@ -54,5 +52,3 @@
 @end
 
 #endif
-
-#endif
diff --git a/Source/WebCore/platform/spi/mac/TUCallSPI.h b/Source/WebCore/platform/spi/mac/TUCallSPI.h
index 61799a1..9b0f882 100644
--- a/Source/WebCore/platform/spi/mac/TUCallSPI.h
+++ b/Source/WebCore/platform/spi/mac/TUCallSPI.h
@@ -23,8 +23,6 @@
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 #import "SoftLinking.h"
 #import <objc/runtime.h>
 
@@ -37,5 +35,3 @@
 
 SOFT_LINK_PRIVATE_FRAMEWORK_OPTIONAL(TelephonyUtilities)
 SOFT_LINK_CLASS(TelephonyUtilities, TUCall)
-
-#endif
diff --git a/Source/WebCore/platform/sql/SQLiteDatabase.cpp b/Source/WebCore/platform/sql/SQLiteDatabase.cpp
index 41110ff..d120378 100644
--- a/Source/WebCore/platform/sql/SQLiteDatabase.cpp
+++ b/Source/WebCore/platform/sql/SQLiteDatabase.cpp
@@ -67,7 +67,7 @@
         // std::call_once is used to stay on the safe side. See bug #143245.
         int ret = sqlite3_initialize();
         if (ret != SQLITE_OK) {
-#if (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000) || (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && SQLITE_VERSION_NUMBER >= 3007015)
+#if PLATFORM(MAC) || SQLITE_VERSION_NUMBER >= 3007015
             WTFLogAlways("Failed to initialize SQLite: %s", sqlite3_errstr(ret));
 #else
             WTFLogAlways("Failed to initialize SQLite");
diff --git a/Source/WebCore/rendering/RenderButton.cpp b/Source/WebCore/rendering/RenderButton.cpp
index d1d0d91..b35310b 100644
--- a/Source/WebCore/rendering/RenderButton.cpp
+++ b/Source/WebCore/rendering/RenderButton.cpp
@@ -41,7 +41,6 @@
     : RenderFlexibleBox(element, WTF::move(style))
     , m_buttonText(0)
     , m_inner(0)
-    , m_default(false)
 {
 }
 
@@ -111,18 +110,6 @@
 
     if (m_inner) // RenderBlock handled updating the anonymous block's style.
         setupInnerStyle(&m_inner->style());
-
-    if (!m_default && theme().isDefault(*this)) {
-        if (theme().defaultButtonHasAnimation()) {
-            if (!m_timer)
-                m_timer = std::make_unique<Timer>(*this, &RenderButton::timerFired);
-            m_timer->startRepeating(0.03);
-        }
-        m_default = true;
-    } else if (m_default && !theme().isDefault(*this)) {
-        m_default = false;
-        m_timer = nullptr;
-    }
 }
 
 void RenderButton::setupInnerStyle(RenderStyle* innerStyle) 
@@ -186,18 +173,6 @@
     return LayoutRect(additionalOffset.x() + borderLeft(), additionalOffset.y() + borderTop(), width() - borderLeft() - borderRight(), height() - borderTop() - borderBottom());
 }
 
-void RenderButton::timerFired()
-{
-    // FIXME Bug 25110: Ideally we would stop our timer when our Document
-    // enters the page cache. But we currently have no way of being notified
-    // when that happens, so we'll just ignore the timer firing as long as
-    // we're in the cache.
-    if (document().inPageCache())
-        return;
-
-    repaint();
-}
-
 #if PLATFORM(IOS)
 void RenderButton::layout()
 {
diff --git a/Source/WebCore/rendering/RenderButton.h b/Source/WebCore/rendering/RenderButton.h
index 8cc8bda..bc08a27 100644
--- a/Source/WebCore/rendering/RenderButton.h
+++ b/Source/WebCore/rendering/RenderButton.h
@@ -74,15 +74,10 @@
 
     virtual bool requiresForcedStyleRecalcPropagation() const override { return true; }
 
-    void timerFired();
-
     bool isFlexibleBoxImpl() const override { return true; }
 
     RenderTextFragment* m_buttonText;
     RenderBlock* m_inner;
-
-    std::unique_ptr<Timer> m_timer;
-    bool m_default;
 };
 
 } // namespace WebCore
diff --git a/Source/WebCore/rendering/RenderTheme.h b/Source/WebCore/rendering/RenderTheme.h
index fc12c5d..8d9167a 100644
--- a/Source/WebCore/rendering/RenderTheme.h
+++ b/Source/WebCore/rendering/RenderTheme.h
@@ -247,8 +247,6 @@
     virtual IntSize imageControlsButtonPositionOffset() const { return IntSize(); }
 #endif
 
-    virtual bool defaultButtonHasAnimation() const { return false; }
-
 #if ENABLE(ATTACHMENT_ELEMENT)
     virtual LayoutSize attachmentIntrinsicSize(const RenderAttachment&) const { return LayoutSize(); }
     virtual int attachmentBaseline(const RenderAttachment&) const { return -1; }
diff --git a/Source/WebCore/rendering/RenderThemeMac.h b/Source/WebCore/rendering/RenderThemeMac.h
index 623dd66..3dd8824 100644
--- a/Source/WebCore/rendering/RenderThemeMac.h
+++ b/Source/WebCore/rendering/RenderThemeMac.h
@@ -100,8 +100,6 @@
     // A view associated to the contained document.
     NSView* documentViewFor(const RenderObject&) const;
 
-    virtual bool defaultButtonHasAnimation() const override;
-
 protected:
     RenderThemeMac();
     virtual ~RenderThemeMac();
diff --git a/Source/WebCore/rendering/RenderThemeMac.mm b/Source/WebCore/rendering/RenderThemeMac.mm
index c080458..43ba38f 100644
--- a/Source/WebCore/rendering/RenderThemeMac.mm
+++ b/Source/WebCore/rendering/RenderThemeMac.mm
@@ -175,11 +175,9 @@
 @implementation WebCoreRenderThemeBundle
 @end
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 @interface NSSearchFieldCell()
 @property (getter=isCenteredLook) BOOL centeredLook;
 @end
-#endif
 
 namespace WebCore {
 
@@ -469,12 +467,8 @@
         color = convertNSColorToColor([NSColor keyboardFocusIndicatorColor]);
         break;
     case CSSValueActivebuttontext:
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         // There is no corresponding NSColor for this so we use a hard coded value.
         color = Color::white;
-#else
-        color = convertNSColorToColor([NSColor controlTextColor]);
-#endif
         break;
     case CSSValueActivecaption:
         color = convertNSColorToColor([NSColor windowFrameTextColor]);
@@ -568,7 +562,6 @@
     case CSSValueWindowtext:
         color = convertNSColorToColor([NSColor windowFrameTextColor]);
         break;
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     case CSSValueAppleWirelessPlaybackTargetActive:
         color = convertNSColorToColor([NSColor systemBlueColor]);
         break;
@@ -599,7 +592,6 @@
     case CSSValueAppleSystemYellow:
         color = convertNSColorToColor([NSColor systemYellowColor]);
         break;
-#endif
     default:
         break;
     }
@@ -933,11 +925,6 @@
 
     GraphicsContextStateSaver stateSaver(paintInfo.context());
 
-    // Before Yosemite we did not want the cell to ever draw outside the given rectangle.
-#if __MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-    paintInfo.context().clip(inflatedRect);
-#endif
-
     if (zoomLevel != 1.0f) {
         inflatedRect.setWidth(inflatedRect.width() / zoomLevel);
         inflatedRect.setHeight(inflatedRect.height() / zoomLevel);
@@ -1971,9 +1958,7 @@
         [m_search.get() setBezeled:YES];
         [m_search.get() setEditable:YES];
         [m_search.get() setFocusRingType:NSFocusRingTypeExterior];
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         [m_search.get() setCenteredLook:NO];
-#endif
     }
 
     return m_search.get();
@@ -2043,15 +2028,6 @@
     return StringTruncator::centerTruncate(strToTruncate, width, font, StringTruncator::EnableRoundingHacks);
 }
 
-bool RenderThemeMac::defaultButtonHasAnimation() const
-{
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-    return false;
-#else
-    return true;
-#endif
-}
-
 #if ENABLE(SERVICE_CONTROLS)
 NSServicesRolloverButtonCell* RenderThemeMac::servicesRolloverButtonCell() const
 {
diff --git a/Source/WebInspectorUI/ChangeLog b/Source/WebInspectorUI/ChangeLog
index 7754fae..c6f32cd 100644
--- a/Source/WebInspectorUI/ChangeLog
+++ b/Source/WebInspectorUI/ChangeLog
@@ -1,3 +1,21 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        - Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
+          that became uniform across all OS X versions as a result:
+
+        * Configurations/Base.xcconfig:
+        * Configurations/DebugRelease.xcconfig:
+        * Configurations/Version.xcconfig:
+
+        * Scripts/copy-user-interface-resources.pl: Removed code to delete Images/Legacy.
+
+        * UserInterface/Images/Legacy: Removed this empty directory.
+
 2015-12-18  Matt Baker  <mattbaker@apple.com>
 
         Web Inspector: Make it possible to debug injected scripts when the Debug UI is enabled
diff --git a/Source/WebInspectorUI/Configurations/Base.xcconfig b/Source/WebInspectorUI/Configurations/Base.xcconfig
index 6780259..536ac70 100644
--- a/Source/WebInspectorUI/Configurations/Base.xcconfig
+++ b/Source/WebInspectorUI/Configurations/Base.xcconfig
@@ -63,14 +63,6 @@
 
 OTHER_LDFLAGS_VERSIONED_FRAMEWORK_PATH = -Wl,-dyld_env -Wl,DYLD_VERSIONED_FRAMEWORK_PATH=/System/Library/StagedFrameworks/Safari;
 
-TOOLCHAINS[sdk=macosx*] = $(TOOLCHAINS_macosx);
-TOOLCHAINS_macosx = $(TOOLCHAINS_macosx_$(MAC_OS_X_VERSION_MAJOR));
-TOOLCHAINS_macosx_1080 = default;
-TOOLCHAINS_macosx_1090 = $(TOOLCHAINS);
-TOOLCHAINS_macosx_101000 = $(TOOLCHAINS_macosx_1090);
-TOOLCHAINS_macosx_101100 = $(TOOLCHAINS_macosx_101000);
-TOOLCHAINS_macosx_101200 = $(TOOLCHAINS_macosx_101100);
-
 OTHER_CFLAGS = $(ASAN_OTHER_CFLAGS);
 OTHER_CPLUSPLUSFLAGS = $(ASAN_OTHER_CPLUSPLUSFLAGS);
 OTHER_LDFLAGS = $(ASAN_OTHER_LDFLAGS);
diff --git a/Source/WebInspectorUI/Configurations/DebugRelease.xcconfig b/Source/WebInspectorUI/Configurations/DebugRelease.xcconfig
index 7e11dff..6164baa 100644
--- a/Source/WebInspectorUI/Configurations/DebugRelease.xcconfig
+++ b/Source/WebInspectorUI/Configurations/DebugRelease.xcconfig
@@ -5,8 +5,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-MACOSX_DEPLOYMENT_TARGET_macosx_1080 = 10.8;
-MACOSX_DEPLOYMENT_TARGET_macosx_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_macosx_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_macosx_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_macosx_101200 = 10.12;
diff --git a/Source/WebInspectorUI/Configurations/Version.xcconfig b/Source/WebInspectorUI/Configurations/Version.xcconfig
index fa55305..f5c001e 100644
--- a/Source/WebInspectorUI/Configurations/Version.xcconfig
+++ b/Source/WebInspectorUI/Configurations/Version.xcconfig
@@ -8,8 +8,6 @@
 // The system version prefix is based on the current system version.
 SYSTEM_VERSION_PREFIX[sdk=iphone*] = 8;
 SYSTEM_VERSION_PREFIX = $(SYSTEM_VERSION_PREFIX_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-SYSTEM_VERSION_PREFIX_macosx_1080 = 8;
-SYSTEM_VERSION_PREFIX_macosx_1090 = 9;
 SYSTEM_VERSION_PREFIX_macosx_101000 = 10;
 SYSTEM_VERSION_PREFIX_macosx_101100 = 11;
 SYSTEM_VERSION_PREFIX_macosx_101200 = 12;
diff --git a/Source/WebInspectorUI/Scripts/copy-user-interface-resources.pl b/Source/WebInspectorUI/Scripts/copy-user-interface-resources.pl
index 6324861..2755150 100755
--- a/Source/WebInspectorUI/Scripts/copy-user-interface-resources.pl
+++ b/Source/WebInspectorUI/Scripts/copy-user-interface-resources.pl
@@ -227,9 +227,6 @@
 
     ditto(File::Spec->catdir($uiRoot, 'Images'), File::Spec->catdir($targetResourcePath, 'Images'));
 
-    # Remove Images/Legacy on modern systems (OS X 10.10 Yosemite and greater or Windows).
-    remove_tree(File::Spec->catdir($targetResourcePath, 'Images', 'Legacy')) if (defined $ENV{'MAC_OS_X_VERSION_MAJOR'} && $ENV{'MAC_OS_X_VERSION_MAJOR'} ge 101000) or defined $ENV{'OFFICIAL_BUILD'};
-
     # Remove Images/gtk on Mac and Windows builds.
     remove_tree(File::Spec->catdir($targetResourcePath, 'Images', 'gtk')) if defined $ENV{'MAC_OS_X_VERSION_MAJOR'} or defined $ENV{'OFFICIAL_BUILD'};
 
diff --git a/Source/WebKit/mac/ChangeLog b/Source/WebKit/mac/ChangeLog
index 5250e02..53cffea 100644
--- a/Source/WebKit/mac/ChangeLog
+++ b/Source/WebKit/mac/ChangeLog
@@ -1,3 +1,31 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        - Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
+          that became uniform across all OS X versions as a result:
+
+        * Configurations/DebugRelease.xcconfig:
+        * Configurations/FeatureDefines.xcconfig:
+        * Configurations/Version.xcconfig:
+        * Configurations/WebKitLegacy.xcconfig:
+
+        - Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
+          never getting compiled:
+
+        * WebCoreSupport/WebInspectorClient.mm:
+        * WebView/WebDynamicScrollBarsView.mm:
+        * WebView/WebHTMLView.mm:
+        * WebView/WebImmediateActionController.h:
+        * WebView/WebImmediateActionController.mm:
+        * WebView/WebView.mm:
+        * WebView/WebViewData.h:
+        * WebView/WebViewData.mm:
+        * WebView/WebViewInternal.h:
+
 2015-12-17  Tim Horton  <timothy_horton@apple.com>
 
         Data detector yellow highlight location is vertically mirrored in WebKit1
diff --git a/Source/WebKit/mac/Configurations/DebugRelease.xcconfig b/Source/WebKit/mac/Configurations/DebugRelease.xcconfig
index a4fcd6c..ed426c2 100644
--- a/Source/WebKit/mac/Configurations/DebugRelease.xcconfig
+++ b/Source/WebKit/mac/Configurations/DebugRelease.xcconfig
@@ -28,7 +28,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-MACOSX_DEPLOYMENT_TARGET_macosx_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_macosx_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_macosx_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_macosx_101200 = 10.12;
@@ -39,7 +38,6 @@
 WEBKIT_SYSTEM_INTERFACE_LIBRARY[sdk=iphoneos*] = WebKitSystemInterfaceIOSDevice$(IPHONEOS_DEPLOYMENT_TARGET);
 WEBKIT_SYSTEM_INTERFACE_LIBRARY[sdk=iphonesimulator*] = WebKitSystemInterfaceIOSSimulator$(IPHONEOS_DEPLOYMENT_TARGET);
 WEBKIT_SYSTEM_INTERFACE_LIBRARY = $(WEBKIT_SYSTEM_INTERFACE_LIBRARY_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_1090 = WebKitSystemInterfaceMavericks;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101000 = WebKitSystemInterfaceYosemite;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101100 = WebKitSystemInterfaceElCapitan;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101200 = $(WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101100);
diff --git a/Source/WebKit/mac/Configurations/FeatureDefines.xcconfig b/Source/WebKit/mac/Configurations/FeatureDefines.xcconfig
index 29e9f10..e364b1b 100644
--- a/Source/WebKit/mac/Configurations/FeatureDefines.xcconfig
+++ b/Source/WebKit/mac/Configurations/FeatureDefines.xcconfig
@@ -35,12 +35,7 @@
 ENABLE_ACCELERATED_2D_CANVAS = ;
 ENABLE_ACCELERATED_OVERFLOW_SCROLLING[sdk=iphone*] = ENABLE_ACCELERATED_OVERFLOW_SCROLLING;
 ENABLE_ATTACHMENT_ELEMENT = ENABLE_ATTACHMENT_ELEMENT;
-ENABLE_AVF_CAPTIONS[sdk=iphone*] = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS[sdk=macosx*] = $(ENABLE_AVF_CAPTIONS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_AVF_CAPTIONS_macosx_1090 = ;
-ENABLE_AVF_CAPTIONS_macosx_101000 = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS_macosx_101100 = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS_macosx_101200 = ENABLE_AVF_CAPTIONS;
+ENABLE_AVF_CAPTIONS = ENABLE_AVF_CAPTIONS;
 ENABLE_CACHE_PARTITIONING = ENABLE_CACHE_PARTITIONING;
 ENABLE_CANVAS_PATH = ENABLE_CANVAS_PATH;
 ENABLE_CANVAS_PROXY = ;
@@ -76,12 +71,7 @@
 ENABLE_ENCRYPTED_MEDIA[sdk=macosx*] = ENABLE_ENCRYPTED_MEDIA;
 ENABLE_ENCRYPTED_MEDIA_V2[sdk=macosx*] = ENABLE_ENCRYPTED_MEDIA_V2;
 ENABLE_FETCH_API = ENABLE_FETCH_API;
-ENABLE_FILTERS_LEVEL_2[sdk=iphone*] = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2[sdk=macosx*] = $(ENABLE_FILTERS_LEVEL_2_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_FILTERS_LEVEL_2_macosx_1090 = ;
-ENABLE_FILTERS_LEVEL_2_macosx_101000 = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2_macosx_101100 = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2_macosx_101200 = ENABLE_FILTERS_LEVEL_2;
+ENABLE_FILTERS_LEVEL_2 = ENABLE_FILTERS_LEVEL_2;
 ENABLE_FONT_LOAD_EVENTS = ;
 ENABLE_FULLSCREEN_API[sdk=macosx*] = ENABLE_FULLSCREEN_API;
 ENABLE_GAMEPAD[sdk=macosx*] = ENABLE_GAMEPAD;
@@ -89,11 +79,7 @@
 ENABLE_GEOLOCATION = ENABLE_GEOLOCATION;
 ENABLE_HIDDEN_PAGE_DOM_TIMER_THROTTLING[sdk=macosx*] = ENABLE_HIDDEN_PAGE_DOM_TIMER_THROTTLING;
 ENABLE_ICONDATABASE[sdk=macosx*] = ENABLE_ICONDATABASE;
-ENABLE_SERVICE_CONTROLS[sdk=macosx*] = $(ENABLE_SERVICE_CONTROLS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_SERVICE_CONTROLS_macosx_1090 = ;
-ENABLE_SERVICE_CONTROLS_macosx_101000 = ENABLE_SERVICE_CONTROLS;
-ENABLE_SERVICE_CONTROLS_macosx_101100 = ENABLE_SERVICE_CONTROLS;
-ENABLE_SERVICE_CONTROLS_macosx_101200 = ENABLE_SERVICE_CONTROLS;
+ENABLE_SERVICE_CONTROLS[sdk=macosx*] = ENABLE_SERVICE_CONTROLS;
 ENABLE_INDEXED_DATABASE = ENABLE_INDEXED_DATABASE;
 ENABLE_INDEXED_DATABASE_IN_WORKERS = ;
 ENABLE_INDIE_UI = ENABLE_INDIE_UI;
@@ -106,16 +92,10 @@
 ENABLE_INPUT_TYPE_TIME[sdk=iphone*] = ENABLE_INPUT_TYPE_TIME;
 ENABLE_INPUT_TYPE_WEEK[sdk=iphone*] = ENABLE_INPUT_TYPE_WEEK;
 
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS[sdk=iphone*] = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS[sdk=macosx*] = $(ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_1090 = ;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101000 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101100 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101200 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
+ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
 
 ENABLE_WIRELESS_PLAYBACK_TARGET[sdk=iphone*] = ENABLE_WIRELESS_PLAYBACK_TARGET;
 ENABLE_WIRELESS_PLAYBACK_TARGET[sdk=macosx*] = $(ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_1090 = ;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101000 = ;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101100 = ENABLE_WIRELESS_PLAYBACK_TARGET;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101200 = ENABLE_WIRELESS_PLAYBACK_TARGET;
@@ -128,7 +108,6 @@
 
 ENABLE_MAC_GESTURE_EVENTS = ;
 ENABLE_MAC_GESTURE_EVENTS[sdk=macosx*] = $(ENABLE_MAC_GESTURE_EVENTS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR)_WITH_INTERNAL_SDK_$(USE_INTERNAL_SDK));
-ENABLE_MAC_GESTURE_EVENTS_macosx_1090_WITH_INTERNAL_SDK_YES = ;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101000_WITH_INTERNAL_SDK_YES = ;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101100_WITH_INTERNAL_SDK_YES = ENABLE_MAC_GESTURE_EVENTS;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101200_WITH_INTERNAL_SDK_YES = ENABLE_MAC_GESTURE_EVENTS;
@@ -148,11 +127,7 @@
 ENABLE_MEDIA_CONTROLS_SCRIPT = ENABLE_MEDIA_CONTROLS_SCRIPT;
 ENABLE_MEDIA_SESSION = ;
 
-ENABLE_MEDIA_SOURCE[sdk=macosx*] = $(ENABLE_MEDIA_SOURCE_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_MEDIA_SOURCE_macosx_1090 = ;
-ENABLE_MEDIA_SOURCE_macosx_101000 = ENABLE_MEDIA_SOURCE;
-ENABLE_MEDIA_SOURCE_macosx_101100 = ENABLE_MEDIA_SOURCE;
-ENABLE_MEDIA_SOURCE_macosx_101200 = ENABLE_MEDIA_SOURCE;
+ENABLE_MEDIA_SOURCE[sdk=macosx*] = ENABLE_MEDIA_SOURCE;
 
 ENABLE_MEDIA_STATISTICS = ;
 ENABLE_MEDIA_STREAM = ENABLE_MEDIA_STREAM;
@@ -170,12 +145,7 @@
 ENABLE_QUOTA = ;
 ENABLE_REQUEST_ANIMATION_FRAME = ENABLE_REQUEST_ANIMATION_FRAME;
 ENABLE_REQUEST_AUTOCOMPLETE = ;
-ENABLE_REMOTE_INSPECTOR[sdk=iphone*] = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR[sdk=macosx*] = $(ENABLE_REMOTE_INSPECTOR_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_REMOTE_INSPECTOR_macosx_1090 = ;
-ENABLE_REMOTE_INSPECTOR_macosx_101000 = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR_macosx_101100 = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR_macosx_101200 = ENABLE_REMOTE_INSPECTOR;
+ENABLE_REMOTE_INSPECTOR = ENABLE_REMOTE_INSPECTOR;
 ENABLE_RESOLUTION_MEDIA_QUERY = ;
 ENABLE_RUBBER_BANDING[sdk=macosx*] = ENABLE_RUBBER_BANDING;
 ENABLE_CSS_SCROLL_SNAP = ENABLE_CSS_SCROLL_SNAP;
@@ -185,12 +155,7 @@
 ENABLE_SVG_FONTS = ENABLE_SVG_FONTS;
 ENABLE_SVG_OTF_CONVERTER = ENABLE_SVG_OTF_CONVERTER;
 
-ENABLE_TELEPHONE_NUMBER_DETECTION[sdk=iphone*] = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION[sdk=macosx*] = $(ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_1090 = ;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101000 = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101100 = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101200 = ENABLE_TELEPHONE_NUMBER_DETECTION;
+ENABLE_TELEPHONE_NUMBER_DETECTION = ENABLE_TELEPHONE_NUMBER_DETECTION;
 
 ENABLE_TEMPLATE_ELEMENT = ENABLE_TEMPLATE_ELEMENT;
 ENABLE_TEXT_AUTOSIZING = ;
@@ -219,12 +184,7 @@
 ENABLE_WEB_REPLAY_macosx_Release = ENABLE_WEB_REPLAY;
 ENABLE_WEB_SOCKETS = ENABLE_WEB_SOCKETS;
 
-ENABLE_WEB_TIMING[sdk=iphone*] = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING[sdk=macosx*] = $(ENABLE_WEB_TIMING_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_WEB_TIMING_macosx_1090 = ;
-ENABLE_WEB_TIMING_macosx_101000 = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING_macosx_101100 = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING_macosx_101200 = ENABLE_WEB_TIMING;
+ENABLE_WEB_TIMING = ENABLE_WEB_TIMING;
 
 ENABLE_XSLT = ENABLE_XSLT;
 
diff --git a/Source/WebKit/mac/Configurations/Version.xcconfig b/Source/WebKit/mac/Configurations/Version.xcconfig
index a68c035..4316163 100644
--- a/Source/WebKit/mac/Configurations/Version.xcconfig
+++ b/Source/WebKit/mac/Configurations/Version.xcconfig
@@ -35,7 +35,6 @@
 // The system version prefix is based on the current system version.
 SYSTEM_VERSION_PREFIX[sdk=iphone*] = 8;
 SYSTEM_VERSION_PREFIX = $(SYSTEM_VERSION_PREFIX_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-SYSTEM_VERSION_PREFIX_macosx_1090 = 9;
 SYSTEM_VERSION_PREFIX_macosx_101000 = 10;
 SYSTEM_VERSION_PREFIX_macosx_101100 = 11;
 SYSTEM_VERSION_PREFIX_macosx_101200 = 12;
diff --git a/Source/WebKit/mac/Configurations/WebKitLegacy.xcconfig b/Source/WebKit/mac/Configurations/WebKitLegacy.xcconfig
index 2c442d3..dcd79a3 100644
--- a/Source/WebKit/mac/Configurations/WebKitLegacy.xcconfig
+++ b/Source/WebKit/mac/Configurations/WebKitLegacy.xcconfig
@@ -49,9 +49,6 @@
 OTHER_CFLAGS[sdk=macosx*] = $(OTHER_CFLAGS) -iframework $(SDKROOT)$(SYSTEM_LIBRARY_DIR)/Frameworks/ApplicationServices.framework/Frameworks -iframework $(SDKROOT)$(SYSTEM_LIBRARY_DIR)/Frameworks/Carbon.framework/Frameworks -iframework $(SDKROOT)$(SYSTEM_LIBRARY_DIR)/Frameworks/Quartz.framework/Frameworks -iframework $(SDKROOT)$(SYSTEM_LIBRARY_DIR)/Frameworks/CoreServices.framework/Frameworks -iframework $(SDKROOT)$(SYSTEM_LIBRARY_DIR)/PrivateFrameworks;
 OTHER_CPLUSPLUSFLAGS = $(OTHER_CFLAGS);
 
-WEBKIT_LEGACY_SYSTEM_FRAMEWORK_MISSING = $(WEBKIT_LEGACY_SYSTEM_FRAMEWORK_MISSING_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-WEBKIT_LEGACY_SYSTEM_FRAMEWORK_MISSING_1090 = YES;
-
 GCC_PREFIX_HEADER = mac/WebKitPrefix.h;
 GCC_PREPROCESSOR_DEFINITIONS = $(DEBUG_DEFINES) $(FEATURE_DEFINES) FRAMEWORK_NAME=WebKitLegacy $(inherited);
 HEADER_SEARCH_PATHS = $(WEBKITSYSTEMINTERFACE_STATIC_LIBRARY_HEADERS_FOLDER_PATH) $(WEBCORE_PRIVATE_HEADERS_DIR)/ForwardingHeaders $(WEBCORE_PRIVATE_HEADERS_DIR)/icu "$(BUILT_PRODUCTS_DIR)/DerivedSources/WebKitLegacy" "$(BUILT_PRODUCTS_DIR)/usr/local/include" $(HEADER_SEARCH_PATHS);
@@ -60,9 +57,7 @@
 INSTALL_PATH[sdk=macosx*] = $(WEBKIT_LEGACY_FRAMEWORKS_DIR);
 
 DYLIB_INSTALL_NAME_BASE[sdk=iphone*] = $(SYSTEM_LIBRARY_DIR)/PrivateFrameworks;
-DYLIB_INSTALL_NAME_BASE = $(DYLIB_INSTALL_NAME_BASE_$(PLATFORM_NAME)_WEBKIT_LEGACY_SYSTEM_FRAMEWORK_MISSING_$(WEBKIT_LEGACY_SYSTEM_FRAMEWORK_MISSING));
-DYLIB_INSTALL_NAME_BASE_macosx_WEBKIT_LEGACY_SYSTEM_FRAMEWORK_MISSING_ = $(NORMAL_WEBKIT_LEGACY_FRAMEWORKS_DIR);
-DYLIB_INSTALL_NAME_BASE_macosx_WEBKIT_LEGACY_SYSTEM_FRAMEWORK_MISSING_YES = $(WEBKIT_LEGACY_FRAMEWORKS_DIR);
+DYLIB_INSTALL_NAME_BASE = $(NORMAL_WEBKIT_LEGACY_FRAMEWORKS_DIR);
 
 INSTALLHDRS_COPY_PHASE = YES;
 INSTALLHDRS_SCRIPT_PHASE = YES;
diff --git a/Source/WebKit/mac/WebCoreSupport/WebInspectorClient.mm b/Source/WebKit/mac/WebCoreSupport/WebInspectorClient.mm
index 6658bec..e6cc240 100644
--- a/Source/WebKit/mac/WebCoreSupport/WebInspectorClient.mm
+++ b/Source/WebKit/mac/WebCoreSupport/WebInspectorClient.mm
@@ -274,9 +274,6 @@
 
 void WebInspectorFrontendClient::setToolbarHeight(unsigned height)
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090
-    [[m_frontendWindowController window] setContentBorderThickness:height forEdge:NSMaxYEdge];
-#endif
 }
 
 void WebInspectorFrontendClient::inspectedURLChanged(const String& newURL)
@@ -398,10 +395,6 @@
     [_frontendWebView setUIDelegate:self];
     [_frontendWebView setPolicyDelegate:self];
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090
-    [_frontendWebView setDrawsBackground:NO];
-#endif
-
     [preferences release];
 
     [self setWindowFrameAutosaveName:@"Web Inspector 2"];
@@ -468,12 +461,7 @@
     if (window)
         return window;
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     NSUInteger styleMask = NSTitledWindowMask | NSClosableWindowMask | NSMiniaturizableWindowMask | NSResizableWindowMask | NSFullSizeContentViewWindowMask;
-#else
-    NSUInteger styleMask = NSTitledWindowMask | NSClosableWindowMask | NSMiniaturizableWindowMask | NSResizableWindowMask | NSTexturedBackgroundWindowMask;
-#endif
-
     window = [[NSWindow alloc] initWithContentRect:NSMakeRect(0, 0, initialWindowWidth, initialWindowHeight) styleMask:styleMask backing:NSBackingStoreBuffered defer:NO];
     [window setDelegate:self];
     [window setMinSize:NSMakeSize(minimumWindowWidth, minimumWindowHeight)];
@@ -486,12 +474,7 @@
     [window setCollectionBehavior:([window collectionBehavior] | NSWindowCollectionBehaviorFullScreenAllowsTiling)];
 #endif
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     window.titlebarAppearsTransparent = YES;
-#else
-    [window setAutorecalculatesContentBorderThickness:NO forEdge:NSMaxYEdge];
-    [window setContentBorderThickness:55. forEdge:NSMaxYEdge];
-#endif
 
     [self setWindow:window];
     [window release];
diff --git a/Source/WebKit/mac/WebView/WebDynamicScrollBarsView.mm b/Source/WebKit/mac/WebView/WebDynamicScrollBarsView.mm
index 66d7ab1..6804e27 100644
--- a/Source/WebKit/mac/WebView/WebDynamicScrollBarsView.mm
+++ b/Source/WebKit/mac/WebView/WebDynamicScrollBarsView.mm
@@ -618,12 +618,10 @@
     return _private->inProgrammaticScroll;
 }
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 - (void)setContentInsets:(NSEdgeInsets)edgeInsets
 {
     [super setContentInsets:edgeInsets];
     [self tile];
 }
-#endif
 
 @end
diff --git a/Source/WebKit/mac/WebView/WebHTMLView.mm b/Source/WebKit/mac/WebView/WebHTMLView.mm
index c75c3fe..2e47f6d 100644
--- a/Source/WebKit/mac/WebView/WebHTMLView.mm
+++ b/Source/WebKit/mac/WebView/WebHTMLView.mm
@@ -4353,7 +4353,7 @@
         frame->eventHandler().wheelEvent(event);
 #endif
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     [[[self _webView] _immediateActionController] webView:[self _webView] didHandleScrollWheel:event];
 #endif
 }
diff --git a/Source/WebKit/mac/WebView/WebImmediateActionController.h b/Source/WebKit/mac/WebView/WebImmediateActionController.h
index febbd95..f818f5f 100644
--- a/Source/WebKit/mac/WebView/WebImmediateActionController.h
+++ b/Source/WebKit/mac/WebView/WebImmediateActionController.h
@@ -23,7 +23,7 @@
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
 
 #import "WebUIDelegatePrivate.h"
 #import <WebCore/HitTestResult.h>
@@ -57,4 +57,4 @@
 
 @end
 
-#endif // PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#endif // PLATFORM(MAC)
diff --git a/Source/WebKit/mac/WebView/WebImmediateActionController.mm b/Source/WebKit/mac/WebView/WebImmediateActionController.mm
index e6d4a5b..9b4f3d5 100644
--- a/Source/WebKit/mac/WebView/WebImmediateActionController.mm
+++ b/Source/WebKit/mac/WebView/WebImmediateActionController.mm
@@ -25,7 +25,7 @@
 
 #import "WebImmediateActionController.h"
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
 
 #import "DOMElementInternal.h"
 #import "DOMNodeInternal.h"
@@ -554,4 +554,4 @@
 
 @end
 
-#endif // PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#endif // PLATFORM(MAC)
diff --git a/Source/WebKit/mac/WebView/WebView.mm b/Source/WebKit/mac/WebView/WebView.mm
index cda3f58..0e9cd31 100644
--- a/Source/WebKit/mac/WebView/WebView.mm
+++ b/Source/WebKit/mac/WebView/WebView.mm
@@ -902,7 +902,7 @@
     [self addSubview:frameView];
     [frameView release];
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     if (Class gestureClass = NSClassFromString(@"NSImmediateActionGestureRecognizer")) {
         RetainPtr<NSImmediateActionGestureRecognizer> recognizer = adoptNS([(NSImmediateActionGestureRecognizer *)[gestureClass alloc] init]);
         _private->immediateActionController = [[WebImmediateActionController alloc] initWithWebView:self recognizer:recognizer.get()];
@@ -1760,7 +1760,7 @@
 
     [_private->inspector inspectedWebViewClosed];
 #endif
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     [_private->immediateActionController webViewClosed];
 #endif
 
@@ -2346,7 +2346,7 @@
     settings.setHttpEquivEnabled([preferences httpEquivEnabled]);
 
     settings.setFixedPositionCreatesStackingContext(true);
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     settings.setAcceleratedCompositingForFixedPositionEnabled(true);
 #endif
 
@@ -5293,7 +5293,7 @@
     _private->page->setDeviceScaleFactor([self _deviceScaleFactor]);
 #endif
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     if (_private->immediateActionController) {
         NSImmediateActionGestureRecognizer *recognizer = [_private->immediateActionController immediateActionRecognizer];
         if ([self window]) {
diff --git a/Source/WebKit/mac/WebView/WebViewData.h b/Source/WebKit/mac/WebView/WebViewData.h
index 89090d3..156d77b 100644
--- a/Source/WebKit/mac/WebView/WebViewData.h
+++ b/Source/WebKit/mac/WebView/WebViewData.h
@@ -172,11 +172,9 @@
     WebNodeHighlight *currentNodeHighlight;
 
 #if PLATFORM(MAC)
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     WebImmediateActionController *immediateActionController;
-#endif // __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200 && USE(APPLE_INTERNAL_SDK)
+#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200 && USE(APPLE_INTERNAL_SDK)
 #import <WebKitAdditions/WebViewDataAdditions.h>
 #endif
 
diff --git a/Source/WebKit/mac/WebView/WebViewData.mm b/Source/WebKit/mac/WebView/WebViewData.mm
index f576d4c..808d108 100644
--- a/Source/WebKit/mac/WebView/WebViewData.mm
+++ b/Source/WebKit/mac/WebView/WebViewData.mm
@@ -181,7 +181,7 @@
 #endif
     [inspector release];
     [currentNodeHighlight release];
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     [immediateActionController release];
 #endif
     [hostWindow release];
diff --git a/Source/WebKit/mac/WebView/WebViewInternal.h b/Source/WebKit/mac/WebView/WebViewInternal.h
index 44147d5..e617cec 100644
--- a/Source/WebKit/mac/WebView/WebViewInternal.h
+++ b/Source/WebKit/mac/WebView/WebViewInternal.h
@@ -271,10 +271,8 @@
 - (void)_clearTextIndicatorWithAnimation:(WebCore::TextIndicatorWindowDismissalAnimation)animation;
 - (void)_setTextIndicatorAnimationProgress:(float)progress;
 - (void)_showDictionaryLookupPopup:(const WebCore::DictionaryPopupInfo&)dictionaryPopupInfo;
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 - (id)_animationControllerForDictionaryLookupPopupInfo:(const WebCore::DictionaryPopupInfo&)dictionaryPopupInfo;
 - (WebImmediateActionController *)_immediateActionController;
-#endif
 - (NSEvent *)_pressureEvent;
 - (void)_setPressureEvent:(NSEvent *)event;
 #endif
diff --git a/Source/WebKit2/ChangeLog b/Source/WebKit2/ChangeLog
index 997bdb7..2696af1 100644
--- a/Source/WebKit2/ChangeLog
+++ b/Source/WebKit2/ChangeLog
@@ -1,3 +1,67 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        - Removed build setting definitions for OS X 10.9 and earlier, and simplified defintions
+          that became uniform across all OS X versions as a result:
+
+        * Configurations/BaseTarget.xcconfig:
+        * Configurations/BaseXPCService.xcconfig:
+        * Configurations/DebugRelease.xcconfig:
+        * Configurations/FeatureDefines.xcconfig:
+        * Configurations/Version.xcconfig:
+        * Configurations/WebKit.xcconfig:
+
+        - Removed the definition of BUNDLE_LOCALIZATION_KEY:
+
+        * Configurations/WebContentService.Development.xcconfig:
+        * Configurations/WebContentService.xcconfig:
+
+        - Added CFBundleFollowParentLocalization set to true:
+
+        * WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-OSX.plist:
+        * WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-iOS.plist:
+        * WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX-10.9-10.10.plist:
+        * WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX.plist:
+        * WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-iOS.plist:
+
+        * WebKit2.xcodeproj/project.pbxproj: Removed the “Add CFBundle Localization Info.plist Key”
+          script build phases from the Web Content Service targets.
+
+        - Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
+          never getting compiled:
+
+        * DatabaseProcess/mac/com.apple.WebKit.Databases.sb.in:
+        * NetworkProcess/cocoa/NetworkProcessCocoa.mm:
+        * NetworkProcess/mac/com.apple.WebKit.NetworkProcess.sb.in:
+        * Platform/IPC/mac/ConnectionMac.mm:
+        * Platform/IPC/mac/ImportanceAssertion.h:
+        * Platform/mac/MenuUtilities.h:
+        * Platform/mac/MenuUtilities.mm:
+        * Platform/mac/StringUtilities.h:
+        * Platform/mac/StringUtilities.mm:
+        * Shared/API/Cocoa/WKFoundation.h:
+        * Shared/EntryPointUtilities/mac/XPCService/XPCServiceMain.Development.mm:
+        * UIProcess/API/Cocoa/WKViewPrivate.h:
+        * UIProcess/API/Cocoa/WKWebView.mm:
+        * UIProcess/API/Cocoa/WKWebViewPrivate.h:
+        * UIProcess/API/mac/WKView.mm:
+        * UIProcess/Cocoa/WebProcessPoolCocoa.mm:
+        * UIProcess/Cocoa/WebViewImpl.h:
+        * UIProcess/Cocoa/WebViewImpl.mm:
+        * UIProcess/Launcher/mac/ProcessLauncherMac.mm:
+        * UIProcess/mac/PageClientImpl.mm:
+        * UIProcess/mac/WKImmediateActionController.h:
+        * UIProcess/mac/WKImmediateActionController.mm:
+        * UIProcess/mac/WebInspectorProxyMac.mm:
+        * WebProcess/WebPage/FindController.cpp:
+        * WebProcess/WebPage/WebPage.cpp:
+        * WebProcess/com.apple.WebProcess.sb.in:
+        * config.h:
+
 2015-12-18  Antti Koivisto  <antti@apple.com>
 
         Cache redirects as separate entries
diff --git a/Source/WebKit2/Configurations/BaseTarget.xcconfig b/Source/WebKit2/Configurations/BaseTarget.xcconfig
index c17c33d..2fd3e3b 100644
--- a/Source/WebKit2/Configurations/BaseTarget.xcconfig
+++ b/Source/WebKit2/Configurations/BaseTarget.xcconfig
@@ -65,7 +65,6 @@
 WK_MANUAL_SANDBOXING_DEFINES_YES = ENABLE_MANUAL_SANDBOXING;
 
 WK_DONT_LINK_SHIM = $(WK_DONT_LINK_SHIM_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-WK_DONT_LINK_SHIM_1090 = YES;
 WK_DONT_LINK_SHIM_101000 = YES;
 
 WK_LINK_SHIM[sdk=macosx*] = $(WK_LINK_SHIM_$(WK_DONT_LINK_SHIM));
diff --git a/Source/WebKit2/Configurations/BaseXPCService.xcconfig b/Source/WebKit2/Configurations/BaseXPCService.xcconfig
index 9c401e3..8cfb0ae 100644
--- a/Source/WebKit2/Configurations/BaseXPCService.xcconfig
+++ b/Source/WebKit2/Configurations/BaseXPCService.xcconfig
@@ -56,5 +56,4 @@
 CODE_SIGN_ENTITLEMENTS_IOS_MANUAL_SANDBOXING_YES = $(BUILT_PRODUCTS_DIR)/DerivedSources/WebKit2/$(WK_XPC_SERVICE_IOS_ENTITLEMENTS_BASE)-no-sandbox.entitlements;
 
 WK_XPC_SERVICE_INFOPLIST_SUFFIX[sdk=macosx*] = $(WK_XPC_SERVICE_INFOPLIST_SUFFIX_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-WK_XPC_SERVICE_INFOPLIST_SUFFIX_1090 = -10.9-10.10;
 WK_XPC_SERVICE_INFOPLIST_SUFFIX_101000 = -10.9-10.10;
diff --git a/Source/WebKit2/Configurations/DebugRelease.xcconfig b/Source/WebKit2/Configurations/DebugRelease.xcconfig
index 527d405a..b543e1b 100644
--- a/Source/WebKit2/Configurations/DebugRelease.xcconfig
+++ b/Source/WebKit2/Configurations/DebugRelease.xcconfig
@@ -28,7 +28,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-MACOSX_DEPLOYMENT_TARGET_macosx_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_macosx_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_macosx_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_macosx_101200 = 10.12;
@@ -39,7 +38,6 @@
 WEBKIT_SYSTEM_INTERFACE_LIBRARY[sdk=iphoneos*] = WebKitSystemInterfaceIOSDevice$(IPHONEOS_DEPLOYMENT_TARGET);
 WEBKIT_SYSTEM_INTERFACE_LIBRARY[sdk=iphonesimulator*] = WebKitSystemInterfaceIOSSimulator$(IPHONEOS_DEPLOYMENT_TARGET);
 WEBKIT_SYSTEM_INTERFACE_LIBRARY = $(WEBKIT_SYSTEM_INTERFACE_LIBRARY_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_1090 = WebKitSystemInterfaceMavericks;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101000 = WebKitSystemInterfaceYosemite;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101100 = WebKitSystemInterfaceElCapitan;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101200 = $(WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101100);
diff --git a/Source/WebKit2/Configurations/FeatureDefines.xcconfig b/Source/WebKit2/Configurations/FeatureDefines.xcconfig
index 29e9f10..e364b1b 100644
--- a/Source/WebKit2/Configurations/FeatureDefines.xcconfig
+++ b/Source/WebKit2/Configurations/FeatureDefines.xcconfig
@@ -35,12 +35,7 @@
 ENABLE_ACCELERATED_2D_CANVAS = ;
 ENABLE_ACCELERATED_OVERFLOW_SCROLLING[sdk=iphone*] = ENABLE_ACCELERATED_OVERFLOW_SCROLLING;
 ENABLE_ATTACHMENT_ELEMENT = ENABLE_ATTACHMENT_ELEMENT;
-ENABLE_AVF_CAPTIONS[sdk=iphone*] = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS[sdk=macosx*] = $(ENABLE_AVF_CAPTIONS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_AVF_CAPTIONS_macosx_1090 = ;
-ENABLE_AVF_CAPTIONS_macosx_101000 = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS_macosx_101100 = ENABLE_AVF_CAPTIONS;
-ENABLE_AVF_CAPTIONS_macosx_101200 = ENABLE_AVF_CAPTIONS;
+ENABLE_AVF_CAPTIONS = ENABLE_AVF_CAPTIONS;
 ENABLE_CACHE_PARTITIONING = ENABLE_CACHE_PARTITIONING;
 ENABLE_CANVAS_PATH = ENABLE_CANVAS_PATH;
 ENABLE_CANVAS_PROXY = ;
@@ -76,12 +71,7 @@
 ENABLE_ENCRYPTED_MEDIA[sdk=macosx*] = ENABLE_ENCRYPTED_MEDIA;
 ENABLE_ENCRYPTED_MEDIA_V2[sdk=macosx*] = ENABLE_ENCRYPTED_MEDIA_V2;
 ENABLE_FETCH_API = ENABLE_FETCH_API;
-ENABLE_FILTERS_LEVEL_2[sdk=iphone*] = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2[sdk=macosx*] = $(ENABLE_FILTERS_LEVEL_2_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_FILTERS_LEVEL_2_macosx_1090 = ;
-ENABLE_FILTERS_LEVEL_2_macosx_101000 = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2_macosx_101100 = ENABLE_FILTERS_LEVEL_2;
-ENABLE_FILTERS_LEVEL_2_macosx_101200 = ENABLE_FILTERS_LEVEL_2;
+ENABLE_FILTERS_LEVEL_2 = ENABLE_FILTERS_LEVEL_2;
 ENABLE_FONT_LOAD_EVENTS = ;
 ENABLE_FULLSCREEN_API[sdk=macosx*] = ENABLE_FULLSCREEN_API;
 ENABLE_GAMEPAD[sdk=macosx*] = ENABLE_GAMEPAD;
@@ -89,11 +79,7 @@
 ENABLE_GEOLOCATION = ENABLE_GEOLOCATION;
 ENABLE_HIDDEN_PAGE_DOM_TIMER_THROTTLING[sdk=macosx*] = ENABLE_HIDDEN_PAGE_DOM_TIMER_THROTTLING;
 ENABLE_ICONDATABASE[sdk=macosx*] = ENABLE_ICONDATABASE;
-ENABLE_SERVICE_CONTROLS[sdk=macosx*] = $(ENABLE_SERVICE_CONTROLS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_SERVICE_CONTROLS_macosx_1090 = ;
-ENABLE_SERVICE_CONTROLS_macosx_101000 = ENABLE_SERVICE_CONTROLS;
-ENABLE_SERVICE_CONTROLS_macosx_101100 = ENABLE_SERVICE_CONTROLS;
-ENABLE_SERVICE_CONTROLS_macosx_101200 = ENABLE_SERVICE_CONTROLS;
+ENABLE_SERVICE_CONTROLS[sdk=macosx*] = ENABLE_SERVICE_CONTROLS;
 ENABLE_INDEXED_DATABASE = ENABLE_INDEXED_DATABASE;
 ENABLE_INDEXED_DATABASE_IN_WORKERS = ;
 ENABLE_INDIE_UI = ENABLE_INDIE_UI;
@@ -106,16 +92,10 @@
 ENABLE_INPUT_TYPE_TIME[sdk=iphone*] = ENABLE_INPUT_TYPE_TIME;
 ENABLE_INPUT_TYPE_WEEK[sdk=iphone*] = ENABLE_INPUT_TYPE_WEEK;
 
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS[sdk=iphone*] = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS[sdk=macosx*] = $(ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_1090 = ;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101000 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101100 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
-ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS_macosx_101200 = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
+ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS = ENABLE_INSPECTOR_ALTERNATE_DISPATCHERS;
 
 ENABLE_WIRELESS_PLAYBACK_TARGET[sdk=iphone*] = ENABLE_WIRELESS_PLAYBACK_TARGET;
 ENABLE_WIRELESS_PLAYBACK_TARGET[sdk=macosx*] = $(ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_1090 = ;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101000 = ;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101100 = ENABLE_WIRELESS_PLAYBACK_TARGET;
 ENABLE_WIRELESS_PLAYBACK_TARGET_macosx_101200 = ENABLE_WIRELESS_PLAYBACK_TARGET;
@@ -128,7 +108,6 @@
 
 ENABLE_MAC_GESTURE_EVENTS = ;
 ENABLE_MAC_GESTURE_EVENTS[sdk=macosx*] = $(ENABLE_MAC_GESTURE_EVENTS_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR)_WITH_INTERNAL_SDK_$(USE_INTERNAL_SDK));
-ENABLE_MAC_GESTURE_EVENTS_macosx_1090_WITH_INTERNAL_SDK_YES = ;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101000_WITH_INTERNAL_SDK_YES = ;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101100_WITH_INTERNAL_SDK_YES = ENABLE_MAC_GESTURE_EVENTS;
 ENABLE_MAC_GESTURE_EVENTS_macosx_101200_WITH_INTERNAL_SDK_YES = ENABLE_MAC_GESTURE_EVENTS;
@@ -148,11 +127,7 @@
 ENABLE_MEDIA_CONTROLS_SCRIPT = ENABLE_MEDIA_CONTROLS_SCRIPT;
 ENABLE_MEDIA_SESSION = ;
 
-ENABLE_MEDIA_SOURCE[sdk=macosx*] = $(ENABLE_MEDIA_SOURCE_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_MEDIA_SOURCE_macosx_1090 = ;
-ENABLE_MEDIA_SOURCE_macosx_101000 = ENABLE_MEDIA_SOURCE;
-ENABLE_MEDIA_SOURCE_macosx_101100 = ENABLE_MEDIA_SOURCE;
-ENABLE_MEDIA_SOURCE_macosx_101200 = ENABLE_MEDIA_SOURCE;
+ENABLE_MEDIA_SOURCE[sdk=macosx*] = ENABLE_MEDIA_SOURCE;
 
 ENABLE_MEDIA_STATISTICS = ;
 ENABLE_MEDIA_STREAM = ENABLE_MEDIA_STREAM;
@@ -170,12 +145,7 @@
 ENABLE_QUOTA = ;
 ENABLE_REQUEST_ANIMATION_FRAME = ENABLE_REQUEST_ANIMATION_FRAME;
 ENABLE_REQUEST_AUTOCOMPLETE = ;
-ENABLE_REMOTE_INSPECTOR[sdk=iphone*] = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR[sdk=macosx*] = $(ENABLE_REMOTE_INSPECTOR_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_REMOTE_INSPECTOR_macosx_1090 = ;
-ENABLE_REMOTE_INSPECTOR_macosx_101000 = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR_macosx_101100 = ENABLE_REMOTE_INSPECTOR;
-ENABLE_REMOTE_INSPECTOR_macosx_101200 = ENABLE_REMOTE_INSPECTOR;
+ENABLE_REMOTE_INSPECTOR = ENABLE_REMOTE_INSPECTOR;
 ENABLE_RESOLUTION_MEDIA_QUERY = ;
 ENABLE_RUBBER_BANDING[sdk=macosx*] = ENABLE_RUBBER_BANDING;
 ENABLE_CSS_SCROLL_SNAP = ENABLE_CSS_SCROLL_SNAP;
@@ -185,12 +155,7 @@
 ENABLE_SVG_FONTS = ENABLE_SVG_FONTS;
 ENABLE_SVG_OTF_CONVERTER = ENABLE_SVG_OTF_CONVERTER;
 
-ENABLE_TELEPHONE_NUMBER_DETECTION[sdk=iphone*] = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION[sdk=macosx*] = $(ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_1090 = ;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101000 = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101100 = ENABLE_TELEPHONE_NUMBER_DETECTION;
-ENABLE_TELEPHONE_NUMBER_DETECTION_macosx_101200 = ENABLE_TELEPHONE_NUMBER_DETECTION;
+ENABLE_TELEPHONE_NUMBER_DETECTION = ENABLE_TELEPHONE_NUMBER_DETECTION;
 
 ENABLE_TEMPLATE_ELEMENT = ENABLE_TEMPLATE_ELEMENT;
 ENABLE_TEXT_AUTOSIZING = ;
@@ -219,12 +184,7 @@
 ENABLE_WEB_REPLAY_macosx_Release = ENABLE_WEB_REPLAY;
 ENABLE_WEB_SOCKETS = ENABLE_WEB_SOCKETS;
 
-ENABLE_WEB_TIMING[sdk=iphone*] = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING[sdk=macosx*] = $(ENABLE_WEB_TIMING_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-ENABLE_WEB_TIMING_macosx_1090 = ;
-ENABLE_WEB_TIMING_macosx_101000 = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING_macosx_101100 = ENABLE_WEB_TIMING;
-ENABLE_WEB_TIMING_macosx_101200 = ENABLE_WEB_TIMING;
+ENABLE_WEB_TIMING = ENABLE_WEB_TIMING;
 
 ENABLE_XSLT = ENABLE_XSLT;
 
diff --git a/Source/WebKit2/Configurations/Version.xcconfig b/Source/WebKit2/Configurations/Version.xcconfig
index d789382..7440b9c 100644
--- a/Source/WebKit2/Configurations/Version.xcconfig
+++ b/Source/WebKit2/Configurations/Version.xcconfig
@@ -35,7 +35,6 @@
 // The system version prefix is based on the current system version.
 SYSTEM_VERSION_PREFIX[sdk=iphone*] = 8;
 SYSTEM_VERSION_PREFIX = $(SYSTEM_VERSION_PREFIX_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-SYSTEM_VERSION_PREFIX_macosx_1090 = 9;
 SYSTEM_VERSION_PREFIX_macosx_101000 = 10;
 SYSTEM_VERSION_PREFIX_macosx_101100 = 11;
 SYSTEM_VERSION_PREFIX_macosx_101200 = 12;
diff --git a/Source/WebKit2/Configurations/WebContentService.Development.xcconfig b/Source/WebKit2/Configurations/WebContentService.Development.xcconfig
index be2570f..929d47c 100644
--- a/Source/WebKit2/Configurations/WebContentService.Development.xcconfig
+++ b/Source/WebKit2/Configurations/WebContentService.Development.xcconfig
@@ -30,12 +30,5 @@
 INFOPLIST_FILE[sdk=iphone*] = WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-iOS.plist;
 INFOPLIST_FILE[sdk=macosx*] = WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-OSX.plist;
 
-BUNDLE_LOCALIZATION_KEY[sdk=iphone*] = CFBundleFollowParentLocalization;
-BUNDLE_LOCALIZATION_KEY = $(BUNDLE_LOCALIZATION_KEY_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-BUNDLE_LOCALIZATION_KEY_macosx_1090 = CFBundleAllowMixedLocalizations;
-BUNDLE_LOCALIZATION_KEY_macosx_101000 = CFBundleFollowParentLocalization;
-BUNDLE_LOCALIZATION_KEY_macosx_101100 = CFBundleFollowParentLocalization;
-BUNDLE_LOCALIZATION_KEY_macosx_101200 = CFBundleFollowParentLocalization;
-
 OTHER_LDFLAGS = $(inherited) $(OTHER_LDFLAGS_VERSIONED_FRAMEWORK_PATH) $(OTHER_LDFLAGS_PLATFORM);
 OTHER_LDFLAGS_PLATFORM[sdk=macosx*] = -framework AppKit;
diff --git a/Source/WebKit2/Configurations/WebContentService.xcconfig b/Source/WebKit2/Configurations/WebContentService.xcconfig
index 4a95a81..dca00cf 100644
--- a/Source/WebKit2/Configurations/WebContentService.xcconfig
+++ b/Source/WebKit2/Configurations/WebContentService.xcconfig
@@ -30,13 +30,6 @@
 INFOPLIST_FILE[sdk=iphone*] = WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-iOS.plist;
 INFOPLIST_FILE[sdk=macosx*] = WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX$(WK_XPC_SERVICE_INFOPLIST_SUFFIX).plist;
 
-BUNDLE_LOCALIZATION_KEY[sdk=iphone*] = CFBundleFollowParentLocalization;
-BUNDLE_LOCALIZATION_KEY = $(BUNDLE_LOCALIZATION_KEY_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-BUNDLE_LOCALIZATION_KEY_macosx_1090 = CFBundleAllowMixedLocalizations;
-BUNDLE_LOCALIZATION_KEY_macosx_101000 = CFBundleFollowParentLocalization;
-BUNDLE_LOCALIZATION_KEY_macosx_101100 = CFBundleFollowParentLocalization;
-BUNDLE_LOCALIZATION_KEY_macosx_101200 = CFBundleFollowParentLocalization;
-
 OTHER_LDFLAGS = $(inherited) $(OTHER_LDFLAGS_VERSIONED_FRAMEWORK_PATH) $(OTHER_LDFLAGS_PLATFORM);
 OTHER_LDFLAGS_PLATFORM[sdk=macosx*] = -framework AppKit $(OTHER_LDFLAGS_SHIM_$(WK_LINK_SHIM));
 OTHER_LDFLAGS_SHIM_YES = $(BUILT_PRODUCTS_DIR)/WebProcessShim.dylib;
diff --git a/Source/WebKit2/Configurations/WebKit.xcconfig b/Source/WebKit2/Configurations/WebKit.xcconfig
index 789cf7e..ad67c74 100644
--- a/Source/WebKit2/Configurations/WebKit.xcconfig
+++ b/Source/WebKit2/Configurations/WebKit.xcconfig
@@ -53,5 +53,4 @@
 INSTALLHDRS_SCRIPT_PHASE = YES;
 
 WK_FRAMEWORK_HEADER_POSTPROCESSING_DISABLED[sdk=macosx*] = $(WK_FRAMEWORK_HEADER_POSTPROCESSING_DISABLED_macosx_$(MAC_OS_X_VERSION_MAJOR));
-WK_FRAMEWORK_HEADER_POSTPROCESSING_DISABLED_macosx_1090 = YES;
 WK_FRAMEWORK_HEADER_POSTPROCESSING_DISABLED_macosx_101000 = YES;
diff --git a/Source/WebKit2/DatabaseProcess/mac/com.apple.WebKit.Databases.sb.in b/Source/WebKit2/DatabaseProcess/mac/com.apple.WebKit.Databases.sb.in
index 7844f11..c4ad89b 100644
--- a/Source/WebKit2/DatabaseProcess/mac/com.apple.WebKit.Databases.sb.in
+++ b/Source/WebKit2/DatabaseProcess/mac/com.apple.WebKit.Databases.sb.in
@@ -74,8 +74,4 @@
 (deny file-write-xattr (xattr "com.apple.quarantine") (with no-log))
 
 ;; Reserve a namespace for additional protected extended attributes.
-#if __MAC_OS_X_VERSION_MIN_REQUIRED > 1090
 (deny file-read-xattr file-write-xattr (xattr-regex #"^com\.apple\.security\.private\."))
-#else
-(deny file-read-xattr file-write-xattr (xattr #"^com\.apple\.security\.private\."))
-#endif
diff --git a/Source/WebKit2/NetworkProcess/cocoa/NetworkProcessCocoa.mm b/Source/WebKit2/NetworkProcess/cocoa/NetworkProcessCocoa.mm
index 3abcf69..f459c59 100644
--- a/Source/WebKit2/NetworkProcess/cocoa/NetworkProcessCocoa.mm
+++ b/Source/WebKit2/NetworkProcess/cocoa/NetworkProcessCocoa.mm
@@ -220,12 +220,10 @@
 
 void NetworkProcess::clearHSTSCache(WebCore::NetworkStorageSession& session, std::chrono::system_clock::time_point modifiedSince)
 {
-#if PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
     NSTimeInterval timeInterval = std::chrono::duration_cast<std::chrono::duration<double>>(modifiedSince.time_since_epoch()).count();
     NSDate *date = [NSDate dateWithTimeIntervalSince1970:timeInterval];
 
     _CFNetworkResetHSTSHostsSinceDate(session.platformSession(), (__bridge CFDateRef)date);
-#endif
 }
 
 static void clearNSURLCache(dispatch_group_t group, std::chrono::system_clock::time_point modifiedSince, const std::function<void ()>& completionHandler)
@@ -233,13 +231,10 @@
     dispatch_group_async(group, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), [modifiedSince, completionHandler] {
         NSURLCache *cache = [NSURLCache sharedURLCache];
 
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         NSTimeInterval timeInterval = std::chrono::duration_cast<std::chrono::duration<double>>(modifiedSince.time_since_epoch()).count();
         NSDate *date = [NSDate dateWithTimeIntervalSince1970:timeInterval];
         [cache removeCachedResponsesSinceDate:date];
-#else
-        [cache removeAllCachedResponses];
-#endif
+
         dispatch_async(dispatch_get_main_queue(), [completionHandler] {
             completionHandler();
         });
diff --git a/Source/WebKit2/NetworkProcess/mac/com.apple.WebKit.NetworkProcess.sb.in b/Source/WebKit2/NetworkProcess/mac/com.apple.WebKit.NetworkProcess.sb.in
index 7362bfa..a27d86c 100644
--- a/Source/WebKit2/NetworkProcess/mac/com.apple.WebKit.NetworkProcess.sb.in
+++ b/Source/WebKit2/NetworkProcess/mac/com.apple.WebKit.NetworkProcess.sb.in
@@ -154,11 +154,7 @@
 (deny file-write-xattr (xattr "com.apple.quarantine") (with no-log))
 
 ;; Reserve a namespace for additional protected extended attributes.
-#if __MAC_OS_X_VERSION_MIN_REQUIRED > 1090
 (deny file-read-xattr file-write-xattr (xattr-regex #"^com\.apple\.security\.private\."))
-#else
-(deny file-read-xattr file-write-xattr (xattr #"^com\.apple\.security\.private\."))
-#endif
 
 (deny file-read* file-write* (with no-log)
     ;; FIXME: Should be removed after <rdar://problem/10463881> is fixed.
diff --git a/Source/WebKit2/Platform/IPC/mac/ConnectionMac.mm b/Source/WebKit2/Platform/IPC/mac/ConnectionMac.mm
index f5f9ce8..8bea8ba 100644
--- a/Source/WebKit2/Platform/IPC/mac/ConnectionMac.mm
+++ b/Source/WebKit2/Platform/IPC/mac/ConnectionMac.mm
@@ -59,7 +59,7 @@
 } AXSuspendStatus;
 #endif
 
-#if !TARGET_OS_IPHONE && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
 extern "C" AXError _AXUIElementNotifyProcessSuspendStatus(AXSuspendStatus);
 #endif
 
@@ -193,10 +193,8 @@
         // Create the receive port.
         mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_RECEIVE, &m_receivePort);
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
         mach_port_set_attributes(mach_task_self(), m_receivePort, MACH_PORT_DENAP_RECEIVER, (mach_port_info_t)0, 0);
-#elif PLATFORM(MAC)
-        mach_port_set_attributes(mach_task_self(), m_receivePort, MACH_PORT_IMPORTANCE_RECEIVER, (mach_port_info_t)0, 0);
 #endif
 
         m_isConnected = true;
@@ -611,7 +609,7 @@
     
 static void AccessibilityProcessSuspendedNotification(bool suspended)
 {
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
     _AXUIElementNotifyProcessSuspendStatus(suspended ? AXSuspendStatusSuspended : AXSuspendStatusRunning);
 #elif PLATFORM(IOS)
     UIAccessibilityPostNotification(kAXPidStatusChangedNotification, @{ @"pid" : @(getpid()), @"suspended" : @(suspended) });
diff --git a/Source/WebKit2/Platform/IPC/mac/ImportanceAssertion.h b/Source/WebKit2/Platform/IPC/mac/ImportanceAssertion.h
index 2379e8e..967af89 100644
--- a/Source/WebKit2/Platform/IPC/mac/ImportanceAssertion.h
+++ b/Source/WebKit2/Platform/IPC/mac/ImportanceAssertion.h
@@ -32,13 +32,8 @@
 #include <libproc_internal.h>
 #endif
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 extern "C" int proc_denap_assertion_begin_with_msg(mach_msg_header_t*, uint64_t *);
 extern "C" int proc_denap_assertion_complete(uint64_t);
-#else
-extern "C" int proc_importance_assertion_begin_with_msg(mach_msg_header_t*, mach_msg_trailer_t*, uint64_t*);
-extern "C" int proc_importance_assertion_complete(uint64_t assertion_handle);
-#endif
 
 namespace IPC {
 
@@ -49,20 +44,12 @@
     explicit ImportanceAssertion(mach_msg_header_t* header)
         : m_assertion(0)
     {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         proc_denap_assertion_begin_with_msg(header, &m_assertion);
-#else
-        proc_importance_assertion_begin_with_msg(header, 0, &m_assertion);
-#endif
     }
 
     ~ImportanceAssertion()
     {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         proc_denap_assertion_complete(m_assertion);
-#else
-        proc_importance_assertion_complete(m_assertion);
-#endif
     }
 
 private:
diff --git a/Source/WebKit2/Platform/mac/MenuUtilities.h b/Source/WebKit2/Platform/mac/MenuUtilities.h
index 0805eb4..876882d 100644
--- a/Source/WebKit2/Platform/mac/MenuUtilities.h
+++ b/Source/WebKit2/Platform/mac/MenuUtilities.h
@@ -31,7 +31,7 @@
 
 namespace WebKit {
 
-#if ENABLE(TELEPHONE_NUMBER_DETECTION) && PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if ENABLE(TELEPHONE_NUMBER_DETECTION) && PLATFORM(MAC)
 NSMenuItem *menuItemForTelephoneNumber(const String& telephoneNumber);
 RetainPtr<NSMenu> menuForTelephoneNumber(const String& telephoneNumber);
 NSString *menuItemTitleForTelephoneNumberGroup();
diff --git a/Source/WebKit2/Platform/mac/MenuUtilities.mm b/Source/WebKit2/Platform/mac/MenuUtilities.mm
index 9228ea5..aaf23f0 100644
--- a/Source/WebKit2/Platform/mac/MenuUtilities.mm
+++ b/Source/WebKit2/Platform/mac/MenuUtilities.mm
@@ -33,13 +33,13 @@
 #import <WebCore/LocalizedStrings.h>
 #import <objc/runtime.h>
 
-#if ENABLE(TELEPHONE_NUMBER_DETECTION) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if ENABLE(TELEPHONE_NUMBER_DETECTION)
 #import <WebCore/TUCallSPI.h>
 #endif
 
 namespace WebKit {
 
-#if ENABLE(TELEPHONE_NUMBER_DETECTION) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if ENABLE(TELEPHONE_NUMBER_DETECTION)
 
 NSString *menuItemTitleForTelephoneNumberGroup()
 {
diff --git a/Source/WebKit2/Platform/mac/StringUtilities.h b/Source/WebKit2/Platform/mac/StringUtilities.h
index 69bd1b8..7284282 100644
--- a/Source/WebKit2/Platform/mac/StringUtilities.h
+++ b/Source/WebKit2/Platform/mac/StringUtilities.h
@@ -34,7 +34,7 @@
 // expects to be called on the thread running WebCore.
 NSString *nsStringFromWebCoreString(const String&);
 
-#if ENABLE(TELEPHONE_NUMBER_DETECTION) && PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if ENABLE(TELEPHONE_NUMBER_DETECTION) && PLATFORM(MAC)
 NSString *formattedPhoneNumberString(NSString *originalPhoneNumber);
 #endif
 
diff --git a/Source/WebKit2/Platform/mac/StringUtilities.mm b/Source/WebKit2/Platform/mac/StringUtilities.mm
index 987a852..7920060 100644
--- a/Source/WebKit2/Platform/mac/StringUtilities.mm
+++ b/Source/WebKit2/Platform/mac/StringUtilities.mm
@@ -39,7 +39,7 @@
     return string.isEmpty() ? @"" : CFBridgingRelease(WKStringCopyCFString(0, toAPI(string.impl())));
 }
 
-#if ENABLE(TELEPHONE_NUMBER_DETECTION) && PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if ENABLE(TELEPHONE_NUMBER_DETECTION) && PLATFORM(MAC)
 
 SOFT_LINK_PRIVATE_FRAMEWORK(PhoneNumbers);
 
@@ -72,6 +72,6 @@
     return [(NSString *)phoneNumberString autorelease];
 }
 
-#endif // ENABLE(TELEPHONE_NUMBER_DETECTION) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#endif // ENABLE(TELEPHONE_NUMBER_DETECTION) && PLATFORM(MAC)
 
 }
diff --git a/Source/WebKit2/Shared/API/Cocoa/WKFoundation.h b/Source/WebKit2/Shared/API/Cocoa/WKFoundation.h
index 3579825..1ebe00e 100644
--- a/Source/WebKit2/Shared/API/Cocoa/WKFoundation.h
+++ b/Source/WebKit2/Shared/API/Cocoa/WKFoundation.h
@@ -113,10 +113,6 @@
 
 #endif
 
-#if defined(__MAC_OS_X_VERSION_MAX_ALLOWED) && __MAC_OS_X_VERSION_MAX_ALLOWED < 101000
-typedef NSUInteger NSEventModifierFlags;
-#endif
-
 #endif
 
 #endif
diff --git a/Source/WebKit2/Shared/EntryPointUtilities/mac/XPCService/XPCServiceMain.Development.mm b/Source/WebKit2/Shared/EntryPointUtilities/mac/XPCService/XPCServiceMain.Development.mm
index 6fcd988..7b3c025 100644
--- a/Source/WebKit2/Shared/EntryPointUtilities/mac/XPCService/XPCServiceMain.Development.mm
+++ b/Source/WebKit2/Shared/EntryPointUtilities/mac/XPCService/XPCServiceMain.Development.mm
@@ -160,7 +160,6 @@
 
 int main(int argc, char** argv)
 {
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if (auto bootstrap = adoptOSObject(xpc_copy_bootstrap())) {
         if (xpc_object_t languages = xpc_dictionary_get_value(bootstrap.get(), "OverrideLanguages")) {
             NSDictionary *existingArguments = [[NSUserDefaults standardUserDefaults] volatileDomainForName:NSArgumentDomain];
@@ -174,9 +173,8 @@
             [[NSUserDefaults standardUserDefaults] setVolatileDomain:newArguments forName:NSArgumentDomain];
         }
     }
-#endif
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
     // Workaround for <rdar://problem/20653234>, make XPC transactions work after re-exec.
diff --git a/Source/WebKit2/UIProcess/API/Cocoa/WKViewPrivate.h b/Source/WebKit2/UIProcess/API/Cocoa/WKViewPrivate.h
index 965c2c5..6c91cae 100644
--- a/Source/WebKit2/UIProcess/API/Cocoa/WKViewPrivate.h
+++ b/Source/WebKit2/UIProcess/API/Cocoa/WKViewPrivate.h
@@ -78,9 +78,7 @@
 
 @property (nonatomic, setter=_setOverrideDeviceScaleFactor:) CGFloat _overrideDeviceScaleFactor WK_AVAILABLE(10_11, NA);
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 @property (nonatomic, setter=_setAutomaticallyAdjustsContentInsets:) BOOL _automaticallyAdjustsContentInsets;
-#endif
 
 @property (readonly) NSColor *_pageExtendedBackgroundColor;
 @property (copy, nonatomic) NSColor *underlayColor;
diff --git a/Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm b/Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm
index 5f0a714..1076726 100644
--- a/Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm
+++ b/Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm
@@ -411,10 +411,8 @@
     _impl = std::make_unique<WebKit::WebViewImpl>(self, self, processPool, WTF::move(pageConfiguration));
     _page = &_impl->page();
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     _impl->setAutomaticallyAdjustsContentInsets(true);
 #endif
-#endif
 
     _page->setBackgroundExtendsBeyondPage(true);
 
@@ -4090,7 +4088,6 @@
     return nil;
 }
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 - (void)_setAutomaticallyAdjustsContentInsets:(BOOL)automaticallyAdjustsContentInsets
 {
     _impl->setAutomaticallyAdjustsContentInsets(automaticallyAdjustsContentInsets);
@@ -4100,7 +4097,6 @@
 {
     return _impl->automaticallyAdjustsContentInsets();
 }
-#endif
 
 - (CGFloat)_minimumLayoutWidth
 {
diff --git a/Source/WebKit2/UIProcess/API/Cocoa/WKWebViewPrivate.h b/Source/WebKit2/UIProcess/API/Cocoa/WKWebViewPrivate.h
index eec7856..2173466 100644
--- a/Source/WebKit2/UIProcess/API/Cocoa/WKWebViewPrivate.h
+++ b/Source/WebKit2/UIProcess/API/Cocoa/WKWebViewPrivate.h
@@ -176,9 +176,7 @@
 @property (nonatomic, setter=_setDrawsBackground:) BOOL _drawsBackground;
 @property (nonatomic, setter=_setTopContentInset:) CGFloat _topContentInset;
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 @property (nonatomic, setter=_setAutomaticallyAdjustsContentInsets:) BOOL _automaticallyAdjustsContentInsets;
-#endif
 
 // Default value is 0. A value of 0 means the window's backing scale factor will be used and automatically update when the window moves screens.
 @property (nonatomic, setter=_setOverrideDeviceScaleFactor:) CGFloat _overrideDeviceScaleFactor WK_AVAILABLE(10_11, NA);
diff --git a/Source/WebKit2/UIProcess/API/mac/WKView.mm b/Source/WebKit2/UIProcess/API/mac/WKView.mm
index 438c40b..7104d64 100644
--- a/Source/WebKit2/UIProcess/API/mac/WKView.mm
+++ b/Source/WebKit2/UIProcess/API/mac/WKView.mm
@@ -1435,8 +1435,6 @@
     _data->_impl->dismissContentRelativeChildWindowsWithAnimationFromViewOnly(withAnimation);
 }
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
-
 - (void)_setAutomaticallyAdjustsContentInsets:(BOOL)automaticallyAdjustsContentInsets
 {
     _data->_impl->setAutomaticallyAdjustsContentInsets(automaticallyAdjustsContentInsets);
@@ -1447,8 +1445,6 @@
     return _data->_impl->automaticallyAdjustsContentInsets();
 }
 
-#endif
-
 @end
 
 #endif // PLATFORM(MAC)
diff --git a/Source/WebKit2/UIProcess/Cocoa/WebProcessPoolCocoa.mm b/Source/WebKit2/UIProcess/Cocoa/WebProcessPoolCocoa.mm
index 7e965f1..5fed0eb 100644
--- a/Source/WebKit2/UIProcess/Cocoa/WebProcessPoolCocoa.mm
+++ b/Source/WebKit2/UIProcess/Cocoa/WebProcessPoolCocoa.mm
@@ -508,13 +508,11 @@
 
 void WebProcessPool::resetHSTSHostsAddedAfterDate(double startDateIntervalSince1970)
 {
-#if PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
     NSDate *startDate = [NSDate dateWithTimeIntervalSince1970:startDateIntervalSince1970];
     _CFNetworkResetHSTSHostsSinceDate(nullptr, (__bridge CFDateRef)startDate);
 #if PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101100)
     _CFNetworkResetHSTSHostsSinceDate(privateBrowsingSession(), (__bridge CFDateRef)startDate);
 #endif
-#endif
 }
 
 int networkProcessLatencyQOS()
diff --git a/Source/WebKit2/UIProcess/Cocoa/WebViewImpl.h b/Source/WebKit2/UIProcess/Cocoa/WebViewImpl.h
index 82b17bc..368991b 100644
--- a/Source/WebKit2/UIProcess/Cocoa/WebViewImpl.h
+++ b/Source/WebKit2/UIProcess/Cocoa/WebViewImpl.h
@@ -563,10 +563,8 @@
     bool m_ignoresAllEvents { false };
     bool m_ignoresMouseDraggedEvents { false };
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     RetainPtr<WKImmediateActionController> m_immediateActionController;
     RetainPtr<NSImmediateActionGestureRecognizer> m_immediateActionGestureRecognizer;
-#endif
 
     bool m_allowsLinkPreview { true };
     bool m_didRegisterForLookupPopoverCloseNotifications { false };
diff --git a/Source/WebKit2/UIProcess/Cocoa/WebViewImpl.mm b/Source/WebKit2/UIProcess/Cocoa/WebViewImpl.mm
index 2c960d4..a2164cb 100644
--- a/Source/WebKit2/UIProcess/Cocoa/WebViewImpl.mm
+++ b/Source/WebKit2/UIProcess/Cocoa/WebViewImpl.mm
@@ -139,9 +139,7 @@
     [super dealloc];
 }
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 static void* keyValueObservingContext = &keyValueObservingContext;
-#endif
 
 - (void)startObserving:(NSWindow *)window
 {
@@ -164,10 +162,9 @@
     [defaultNotificationCenter addObserver:self selector:@selector(_windowDidChangeScreen:) name:NSWindowDidChangeScreenNotification object:window];
     [defaultNotificationCenter addObserver:self selector:@selector(_windowDidChangeLayerHosting:) name:@"_NSWindowDidChangeContentsHostedInLayerSurfaceNotification" object:window];
     [defaultNotificationCenter addObserver:self selector:@selector(_windowDidChangeOcclusionState:) name:NSWindowDidChangeOcclusionStateNotification object:window];
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+
     [window addObserver:self forKeyPath:@"contentLayoutRect" options:NSKeyValueObservingOptionInitial context:keyValueObservingContext];
     [window addObserver:self forKeyPath:@"titlebarAppearsTransparent" options:NSKeyValueObservingOptionInitial context:keyValueObservingContext];
-#endif
 }
 
 - (void)stopObserving:(NSWindow *)window
@@ -190,19 +187,16 @@
     [defaultNotificationCenter removeObserver:self name:NSWindowDidChangeScreenNotification object:window];
     [defaultNotificationCenter removeObserver:self name:@"_NSWindowDidChangeContentsHostedInLayerSurfaceNotification" object:window];
     [defaultNotificationCenter removeObserver:self name:NSWindowDidChangeOcclusionStateNotification object:window];
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+
     if (_impl->isEditable())
         [[NSFontPanel sharedFontPanel] removeObserver:self forKeyPath:@"visible" context:keyValueObservingContext];
     [window removeObserver:self forKeyPath:@"contentLayoutRect" context:keyValueObservingContext];
     [window removeObserver:self forKeyPath:@"titlebarAppearsTransparent" context:keyValueObservingContext];
-#endif
 }
 
 - (void)startObservingFontPanel
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     [[NSFontPanel sharedFontPanel] addObserver:self forKeyPath:@"visible" options:0 context:keyValueObservingContext];
-#endif
 }
 
 - (void)startObservingLookupDismissal
@@ -274,7 +268,6 @@
 
 - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if (context != keyValueObservingContext) {
         [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
         return;
@@ -286,7 +279,6 @@
     }
     if ([keyPath isEqualToString:@"contentLayoutRect"] || [keyPath isEqualToString:@"titlebarAppearsTransparent"])
         _impl->updateContentInsetsIfAutomatic();
-#endif
 }
 
 - (void)_dictionaryLookupPopoverWillClose:(NSNotification *)notification
@@ -459,15 +451,12 @@
 
     m_page->setIntrinsicDeviceScaleFactor(intrinsicDeviceScaleFactor());
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if (Class gestureClass = NSClassFromString(@"NSImmediateActionGestureRecognizer")) {
         m_immediateActionGestureRecognizer = adoptNS([(NSImmediateActionGestureRecognizer *)[gestureClass alloc] init]);
         m_immediateActionController = adoptNS([[WKImmediateActionController alloc] initWithPage:m_page view:m_view viewImpl:*this recognizer:m_immediateActionGestureRecognizer.get()]);
         [m_immediateActionGestureRecognizer setDelegate:m_immediateActionController.get()];
         [m_immediateActionGestureRecognizer setDelaysPrimaryMouseButtonEvents:NO];
     }
-#endif
-
 
     m_page->setAddsVisitedLinks(processPool.historyClient().addsVisitedLinks());
 
@@ -502,9 +491,7 @@
 
     [m_layoutStrategy invalidate];
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     [m_immediateActionController willDestroyView:m_view];
-#endif
 
     m_page->close();
 
@@ -800,7 +787,6 @@
 
 void WebViewImpl::updateContentInsetsIfAutomatic()
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if (!m_automaticallyAdjustsContentInsets)
         return;
 
@@ -812,7 +798,6 @@
             setTopContentInset(newTopContentInset);
     } else
         setTopContentInset(0);
-#endif
 }
 
 void WebViewImpl::setTopContentInset(CGFloat contentInset)
@@ -1182,10 +1167,8 @@
 
         accessibilityRegisterUIProcessTokens();
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         if (m_immediateActionGestureRecognizer && ![[m_view gestureRecognizers] containsObject:m_immediateActionGestureRecognizer.get()] && !m_ignoresNonWheelEvents && m_allowsLinkPreview)
             [m_view addGestureRecognizer:m_immediateActionGestureRecognizer.get()];
-#endif
     } else {
         WebCore::ViewState::Flags viewStateChanges = WebCore::ViewState::WindowIsActive | WebCore::ViewState::IsVisible;
         if (m_isDeferringViewInWindowChanges)
@@ -1199,10 +1182,8 @@
 
         dismissContentRelativeChildWindowsWithAnimation(false);
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         if (m_immediateActionGestureRecognizer)
             [m_view removeGestureRecognizer:m_immediateActionGestureRecognizer.get()];
-#endif
     }
 
     m_page->setIntrinsicDeviceScaleFactor(intrinsicDeviceScaleFactor());
@@ -2158,27 +2139,21 @@
 void WebViewImpl::dismissContentRelativeChildWindowsFromViewOnly()
 {
     bool hasActiveImmediateAction = false;
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     hasActiveImmediateAction = [m_immediateActionController hasActiveImmediateAction];
-#endif
 
     // FIXME: We don't know which panel we are dismissing, it may not even be in the current page (see <rdar://problem/13875766>).
     if (m_view.window.isKeyWindow || hasActiveImmediateAction) {
         WebCore::DictionaryLookup::hidePopup();
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
         DDActionsManager *actionsManager = [getDDActionsManagerClass() sharedManager];
         if ([actionsManager respondsToSelector:@selector(requestBubbleClosureUnanchorOnFailure:)])
             [actionsManager requestBubbleClosureUnanchorOnFailure:YES];
-#endif
     }
 
     clearTextIndicatorWithAnimation(WebCore::TextIndicatorWindowDismissalAnimation::FadeOut);
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     [m_immediateActionController dismissContentRelativeChildWindows];
-#endif
-    
+
     m_pageClient->dismissCorrectionPanel(WebCore::ReasonForDismissingAlternativeTextIgnored);
 }
 
@@ -2192,12 +2167,10 @@
     if (ignoresNonWheelEvents())
         return;
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if (m_immediateActionGestureRecognizer) {
         [m_view _web_superQuickLookWithEvent:event];
         return;
     }
-#endif
 
     NSPoint locationInViewCoordinates = [m_view convertPoint:[event locationInWindow] fromView:nil];
     m_page->performDictionaryLookupAtLocation(WebCore::FloatPoint(locationInViewCoordinates));
@@ -2220,12 +2193,10 @@
 
     m_allowsLinkPreview = allowsLinkPreview;
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if (!allowsLinkPreview)
         [m_view removeGestureRecognizer:m_immediateActionGestureRecognizer.get()];
     else if (NSGestureRecognizer *immediateActionRecognizer = m_immediateActionGestureRecognizer.get())
         [m_view addGestureRecognizer:immediateActionRecognizer];
-#endif
 }
 
 void* WebViewImpl::immediateActionAnimationControllerForHitTestResult(API::HitTestResult* hitTestResult, uint32_t type, API::Object* userData)
@@ -2235,9 +2206,7 @@
 
 void WebViewImpl::didPerformImmediateActionHitTest(const WebHitTestResultData& result, bool contentPreventsDefault, API::Object* userData)
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     [m_immediateActionController didPerformImmediateActionHitTest:result contentPreventsDefault:contentPreventsDefault userData:userData];
-#endif
 }
 
 void WebViewImpl::prepareForImmediateActionAnimation()
@@ -2268,14 +2237,12 @@
     m_ignoresNonWheelEvents = ignoresNonWheelEvents;
     m_page->setShouldDispatchFakeMouseMoveEvents(!ignoresNonWheelEvents);
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     if (ignoresNonWheelEvents)
         [m_view removeGestureRecognizer:m_immediateActionGestureRecognizer.get()];
     else if (NSGestureRecognizer *immediateActionRecognizer = m_immediateActionGestureRecognizer.get()) {
         if (m_allowsLinkPreview)
             [m_view addGestureRecognizer:immediateActionRecognizer];
     }
-#endif
 }
 
 void WebViewImpl::setIgnoresAllEvents(bool ignoresAllEvents)
diff --git a/Source/WebKit2/UIProcess/Launcher/mac/ProcessLauncherMac.mm b/Source/WebKit2/UIProcess/Launcher/mac/ProcessLauncherMac.mm
index 7e23f77..a8a4c84 100644
--- a/Source/WebKit2/UIProcess/Launcher/mac/ProcessLauncherMac.mm
+++ b/Source/WebKit2/UIProcess/Launcher/mac/ProcessLauncherMac.mm
@@ -203,13 +203,8 @@
 {
     // Create a connection to the WebKit XPC service.
     auto connection = adoptOSObject(xpc_connection_create(serviceName(launchOptions, forDevelopment), 0));
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     xpc_connection_set_oneshot_instance(connection.get(), instanceUUID->uuid);
-#else
-    xpc_connection_set_instance(connection.get(), instanceUUID->uuid);
-#endif
 
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     // Inherit UI process localization. It can be different from child process default localization:
     // 1. When the application and system frameworks simply have different localized resources available, we should match the application.
     // 1.1. An important case is WebKitTestRunner, where we should use English localizations for all system frameworks.
@@ -239,7 +234,6 @@
     }
 
     xpc_connection_set_bootstrap(connection.get(), initializationMessage.get());
-#endif
 
     // XPC requires having an event handler, even if it is not used.
     xpc_connection_set_event_handler(connection.get(), ^(xpc_object_t event) { });
@@ -335,11 +329,7 @@
     // FIXME: It would be nice if we could use OSObjectPtr for this connection as well, but we'd have to be careful
     // not to introduce any retain cycles in the call to xpc_connection_set_event_handler below.
     xpc_connection_t reExecConnection = xpc_connection_create(serviceName(launchOptions, true), 0);
-#if PLATFORM(IOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     xpc_connection_set_oneshot_instance(reExecConnection, instanceUUID->uuid);
-#else
-    xpc_connection_set_instance(reExecConnection, instanceUUID->uuid);
-#endif
 
     // Keep the ProcessLauncher alive while we do the re-execing (balanced in event handler).
     that->ref();
diff --git a/Source/WebKit2/UIProcess/mac/PageClientImpl.mm b/Source/WebKit2/UIProcess/mac/PageClientImpl.mm
index 896b3d6..b1e27c5 100644
--- a/Source/WebKit2/UIProcess/mac/PageClientImpl.mm
+++ b/Source/WebKit2/UIProcess/mac/PageClientImpl.mm
@@ -771,9 +771,7 @@
 
 void PageClientImpl::didPerformImmediateActionHitTest(const WebHitTestResultData& result, bool contentPreventsDefault, API::Object* userData)
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     m_impl->didPerformImmediateActionHitTest(result, contentPreventsDefault, userData);
-#endif
 }
 
 void* PageClientImpl::immediateActionAnimationControllerForHitTestResult(RefPtr<API::HitTestResult> hitTestResult, uint64_t type, RefPtr<API::Object> userData)
diff --git a/Source/WebKit2/UIProcess/mac/WKImmediateActionController.h b/Source/WebKit2/UIProcess/mac/WKImmediateActionController.h
index 3f6a985..89fd9ad 100644
--- a/Source/WebKit2/UIProcess/mac/WKImmediateActionController.h
+++ b/Source/WebKit2/UIProcess/mac/WKImmediateActionController.h
@@ -26,7 +26,7 @@
 #ifndef WKImmediateActionController_h
 #define WKImmediateActionController_h
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
 
 #import "WKImmediateActionTypes.h"
 #import "WebHitTestResultData.h"
@@ -76,6 +76,6 @@
 
 @end
 
-#endif // PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#endif // PLATFORM(MAC)
 
 #endif // WKImmediateActionController_h
diff --git a/Source/WebKit2/UIProcess/mac/WKImmediateActionController.mm b/Source/WebKit2/UIProcess/mac/WKImmediateActionController.mm
index 47b41d6..80baa98 100644
--- a/Source/WebKit2/UIProcess/mac/WKImmediateActionController.mm
+++ b/Source/WebKit2/UIProcess/mac/WKImmediateActionController.mm
@@ -26,7 +26,7 @@
 #import "config.h"
 #import "WKImmediateActionController.h"
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+#if PLATFORM(MAC)
 
 #import "APIHitTestResult.h"
 #import "WKNSURLExtras.h"
diff --git a/Source/WebKit2/UIProcess/mac/WebInspectorProxyMac.mm b/Source/WebKit2/UIProcess/mac/WebInspectorProxyMac.mm
index 8f406b4..3ca37b3 100644
--- a/Source/WebKit2/UIProcess/mac/WebInspectorProxyMac.mm
+++ b/Source/WebKit2/UIProcess/mac/WebInspectorProxyMac.mm
@@ -55,16 +55,7 @@
 using namespace WebCore;
 using namespace WebKit;
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090
-// The height needed to match a typical NSToolbar.
-static const CGFloat windowContentBorderThickness = 55;
-#endif
-
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 static const NSUInteger windowStyleMask = NSTitledWindowMask | NSClosableWindowMask | NSMiniaturizableWindowMask | NSResizableWindowMask | NSFullSizeContentViewWindowMask;
-#else
-static const NSUInteger windowStyleMask = NSTitledWindowMask | NSClosableWindowMask | NSMiniaturizableWindowMask | NSResizableWindowMask | NSTexturedBackgroundWindowMask;
-#endif
 
 // The time we keep our WebView alive before closing it and its process.
 // Reusing the WebView improves start up time for people that jump in and out of the Inspector.
@@ -301,12 +292,7 @@
     [window setCollectionBehavior:([window collectionBehavior] | NSWindowCollectionBehaviorFullScreenAllowsTiling)];
 #endif
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     window.titlebarAppearsTransparent = YES;
-#else
-    [window setAutorecalculatesContentBorderThickness:NO forEdge:NSMaxYEdge];
-    [window setContentBorderThickness:windowContentBorderThickness forEdge:NSMaxYEdge];
-#endif
 
     m_inspectorWindow = adoptNS(window);
 
@@ -395,13 +381,7 @@
     m_inspectorView = adoptNS([[WKWebInspectorWKWebView alloc] initWithFrame:initialRect configuration:configuration.get()]);
     ASSERT(m_inspectorView);
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 10900
-    m_inspectorView->_page->setDrawsBackground(false);
-#endif
-
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     [m_inspectorView _setAutomaticallyAdjustsContentInsets:NO];
-#endif
 
     m_inspectorProxyObjCAdapter = adoptNS([[WKWebInspectorProxyObjCAdapter alloc] initWithWebInspectorProxy:this]);
     ASSERT(m_inspectorProxyObjCAdapter);
@@ -806,9 +786,6 @@
 
 void WebInspectorProxy::platformSetToolbarHeight(unsigned height)
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090
-    [m_inspectorWindow setContentBorderThickness:height forEdge:NSMaxYEdge];
-#endif
 }
 
 void WebInspectorProxy::platformStartWindowDrag()
diff --git a/Source/WebKit2/WebKit2.xcodeproj/project.pbxproj b/Source/WebKit2/WebKit2.xcodeproj/project.pbxproj
index 8b3511c..17cfb25 100644
--- a/Source/WebKit2/WebKit2.xcodeproj/project.pbxproj
+++ b/Source/WebKit2/WebKit2.xcodeproj/project.pbxproj
@@ -8633,7 +8633,6 @@
 				BC3DE46215A91763008D26FC /* Sources */,
 				BCDC308D15FDB99A006B6695 /* Frameworks */,
 				BC3DE46415A91763008D26FC /* Resources */,
-				E19C7DDB194A5E9100F1866F /* Add CFBundle Localization Info.plist Key */,
 			);
 			buildRules = (
 			);
@@ -8742,7 +8741,6 @@
 				BCAE9DE5160C097400A33217 /* Sources */,
 				BCAE9DE6160C097400A33217 /* Frameworks */,
 				BCAE9DE7160C097400A33217 /* Resources */,
-				E19C7DDA194A4C9500F1866F /* Add CFBundle Localization Info.plist Key */,
 			);
 			buildRules = (
 			);
@@ -9256,34 +9254,6 @@
 			shellPath = /bin/sh;
 			shellScript = "mkdir -p \"${BUILT_PRODUCTS_DIR}/DerivedSources/WebKit2\"\ncd \"${BUILT_PRODUCTS_DIR}/DerivedSources/WebKit2\"\n\nexport WebKit2=\"${SRCROOT}\"\n\nif [ ! $CC ]; then\n    export CC=\"`xcrun -find clang`\"\nfi\n\nif [ \"${ACTION}\" = \"build\" -o \"${ACTION}\" = \"install\" -o \"${ACTION}\" = \"installhdrs\" ]; then\n    make --no-builtin-rules -f \"${WebKit2}/DerivedSources.make\" -j `/usr/sbin/sysctl -n hw.activecpu` SDKROOT=${SDKROOT}\nfi\n";
 		};
-		E19C7DDA194A4C9500F1866F /* Add CFBundle Localization Info.plist Key */ = {
-			isa = PBXShellScriptBuildPhase;
-			buildActionMask = 2147483647;
-			files = (
-			);
-			inputPaths = (
-			);
-			name = "Add CFBundle Localization Info.plist Key";
-			outputPaths = (
-			);
-			runOnlyForDeploymentPostprocessing = 0;
-			shellPath = /bin/sh;
-			shellScript = "/usr/libexec/PlistBuddy -c \"Print :$BUNDLE_LOCALIZATION_KEY\" $TARGET_BUILD_DIR/$INFOPLIST_PATH >/dev/null 2>/dev/null\nif [[ $? != 0 ]]; then\n    echo \"Updating the Info.plist key\"\n    /usr/libexec/PlistBuddy -c \"Delete :CFBundleAllowMixedLocalizations\" $TARGET_BUILD_DIR/$INFOPLIST_PATH 2>/dev/null\n    /usr/libexec/PlistBuddy -c \"Delete :CFBundleFollowParentLocalization\" $TARGET_BUILD_DIR/$INFOPLIST_PATH 2>/dev/null\n    /usr/libexec/PlistBuddy -c \"Add :$BUNDLE_LOCALIZATION_KEY bool true\" $TARGET_BUILD_DIR/$INFOPLIST_PATH\n    if [[ ${PLIST_FILE_OUTPUT_FORMAT} == \"binary\" ]]; then\n        plutil -convert binary1 \"${TARGET_BUILD_DIR}/${INFOPLIST_PATH}\" || exit $?\n    fi\n    echo \"Done\"\nfi\n";
-		};
-		E19C7DDB194A5E9100F1866F /* Add CFBundle Localization Info.plist Key */ = {
-			isa = PBXShellScriptBuildPhase;
-			buildActionMask = 2147483647;
-			files = (
-			);
-			inputPaths = (
-			);
-			name = "Add CFBundle Localization Info.plist Key";
-			outputPaths = (
-			);
-			runOnlyForDeploymentPostprocessing = 0;
-			shellPath = /bin/sh;
-			shellScript = "/usr/libexec/PlistBuddy -c \"Print :$BUNDLE_LOCALIZATION_KEY\" $TARGET_BUILD_DIR/$INFOPLIST_PATH >/dev/null 2>/dev/null\nif [[ $? != 0 ]]; then\n    echo \"Updating the Info.plist key\"\n    /usr/libexec/PlistBuddy -c \"Delete :CFBundleAllowMixedLocalizations\" $TARGET_BUILD_DIR/$INFOPLIST_PATH 2>/dev/null\n    /usr/libexec/PlistBuddy -c \"Delete :CFBundleFollowParentLocalization\" $TARGET_BUILD_DIR/$INFOPLIST_PATH 2>/dev/null\n    /usr/libexec/PlistBuddy -c \"Add :$BUNDLE_LOCALIZATION_KEY bool true\" $TARGET_BUILD_DIR/$INFOPLIST_PATH\n    if [[ ${PLIST_FILE_OUTPUT_FORMAT} == \"binary\" ]]; then\n        plutil -convert binary1 \"${TARGET_BUILD_DIR}/${INFOPLIST_PATH}\" || exit $?\n    fi\n    echo \"Done\"\nfi\n";
-		};
 /* End PBXShellScriptBuildPhase section */
 
 /* Begin PBXSourcesBuildPhase section */
diff --git a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-OSX.plist b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-OSX.plist
index 44967f6..77756ac 100644
--- a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-OSX.plist
+++ b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-OSX.plist
@@ -2,6 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>CFBundleFollowParentLocalization</key>
+	<true/>
 	<key>CFBundleGetInfoString</key>
 	<string>${BUNDLE_VERSION}, Copyright 2003-2015 Apple Inc.</string>
 	<key>CFBundleDevelopmentRegion</key>
diff --git a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-iOS.plist b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-iOS.plist
index 6c4ab01..c4b8c74 100644
--- a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-iOS.plist
+++ b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/Info-iOS.plist
@@ -2,6 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>CFBundleFollowParentLocalization</key>
+	<true/>
 	<key>CFBundleGetInfoString</key>
 	<string>${BUNDLE_VERSION}, Copyright 2003-2015 Apple Inc.</string>
 	<key>CFBundleDevelopmentRegion</key>
diff --git a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX-10.9-10.10.plist b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX-10.9-10.10.plist
index 532e331..4f4acf8 100644
--- a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX-10.9-10.10.plist
+++ b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX-10.9-10.10.plist
@@ -2,6 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>CFBundleFollowParentLocalization</key>
+	<true/>
 	<key>CFBundleGetInfoString</key>
 	<string>${BUNDLE_VERSION}, Copyright 2003-2015 Apple Inc.</string>
 	<key>CFBundleDevelopmentRegion</key>
diff --git a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX.plist b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX.plist
index 1addf7a..64408d7 100644
--- a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX.plist
+++ b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-OSX.plist
@@ -2,6 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>CFBundleFollowParentLocalization</key>
+	<true/>
 	<key>CFBundleGetInfoString</key>
 	<string>${BUNDLE_VERSION}, Copyright 2003-2015 Apple Inc.</string>
 	<key>CFBundleDevelopmentRegion</key>
diff --git a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-iOS.plist b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-iOS.plist
index 9930aba..5e34683 100644
--- a/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-iOS.plist
+++ b/Source/WebKit2/WebProcess/EntryPoint/mac/XPCService/WebContentService/Info-iOS.plist
@@ -2,6 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>CFBundleFollowParentLocalization</key>
+	<true/>
 	<key>CFBundleGetInfoString</key>
 	<string>${BUNDLE_VERSION}, Copyright 2003-2015 Apple Inc.</string>
 	<key>CFBundleDevelopmentRegion</key>
@@ -38,6 +40,6 @@
 	<key>UIBackgroundModes</key>
 	<array>
 		<string>audio</string>
-	</array>	
+	</array>
 </dict>
 </plist>
diff --git a/Source/WebKit2/WebProcess/WebPage/FindController.cpp b/Source/WebKit2/WebProcess/WebPage/FindController.cpp
index 41ce602..d30e7c8 100644
--- a/Source/WebKit2/WebProcess/WebPage/FindController.cpp
+++ b/Source/WebKit2/WebProcess/WebPage/FindController.cpp
@@ -50,12 +50,6 @@
 
 using namespace WebCore;
 
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-#define ENABLE_LEGACY_FIND_INDICATOR_STYLE 1
-#else
-#define ENABLE_LEGACY_FIND_INDICATOR_STYLE 0
-#endif
-
 namespace WebKit {
 
 static WebCore::FindOptions core(FindOptions options)
@@ -446,17 +440,10 @@
 {
 }
 
-#if ENABLE(LEGACY_FIND_INDICATOR_STYLE)
-const float shadowOffsetX = 0;
-const float shadowOffsetY = 1;
-const float shadowBlurRadius = 2;
-const float shadowColorAlpha = 1;
-#else
 const float shadowOffsetX = 0;
 const float shadowOffsetY = 0;
 const float shadowBlurRadius = 1;
 const float shadowColorAlpha = 0.5;
-#endif
 
 void FindController::drawRect(PageOverlay&, GraphicsContext& graphicsContext, const IntRect& dirtyRect)
 {
diff --git a/Source/WebKit2/WebProcess/WebPage/WebPage.cpp b/Source/WebKit2/WebProcess/WebPage/WebPage.cpp
index 8fe67d1..bb77dfd 100644
--- a/Source/WebKit2/WebProcess/WebPage/WebPage.cpp
+++ b/Source/WebKit2/WebProcess/WebPage/WebPage.cpp
@@ -5009,9 +5009,6 @@
     
 bool WebPage::synchronousMessagesShouldSpinRunLoop()
 {
-#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-    return WebCore::AXObjectCache::accessibilityEnabled();
-#endif
     return false;
 }
 
diff --git a/Source/WebKit2/WebProcess/com.apple.WebProcess.sb.in b/Source/WebKit2/WebProcess/com.apple.WebProcess.sb.in
index e7196fe..c608bf4 100644
--- a/Source/WebKit2/WebProcess/com.apple.WebProcess.sb.in
+++ b/Source/WebKit2/WebProcess/com.apple.WebProcess.sb.in
@@ -194,10 +194,8 @@
        (global-name "com.apple.speech.speechsynthesisd")
        (global-name "com.apple.speech.synthesis.console")
        (global-name "com.apple.coreservices.launchservicesd")
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
        (global-name "com.apple.iconservices")
        (global-name "com.apple.iconservices.store")
-#endif
 #if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101100
        (global-name "com.apple.nesessionmanager.flow-divert-token")
 #endif
@@ -277,11 +275,7 @@
 (deny file-write-xattr (xattr "com.apple.quarantine") (with no-log))
 
 ;; Reserve a namespace for additional protected extended attributes.
-#if __MAC_OS_X_VERSION_MIN_REQUIRED > 1090
 (deny file-read-xattr file-write-xattr (xattr-regex #"^com\.apple\.security\.private\."))
-#else
-(deny file-read-xattr file-write-xattr (xattr #"^com\.apple\.security\.private\."))
-#endif
 
 (deny file-read* file-write* (with no-log)
        ;; FIXME: Should be removed after <rdar://problem/10463881> is fixed.
diff --git a/Source/WebKit2/config.h b/Source/WebKit2/config.h
index 24e30a4..a26e76b 100644
--- a/Source/WebKit2/config.h
+++ b/Source/WebKit2/config.h
@@ -79,13 +79,13 @@
 #endif
 
 #ifndef HAVE_SEC_ACCESS_CONTROL
-#if PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#if PLATFORM(IOS) || PLATFORM(MAC)
 #define HAVE_SEC_ACCESS_CONTROL 1
 #endif
 #endif
 
 #ifndef HAVE_OS_ACTIVITY
-#if PLATFORM(IOS) || (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000)
+#if PLATFORM(IOS) || PLATFORM(MAC)
 #define HAVE_OS_ACTIVITY 1
 #endif
 #endif
diff --git a/Source/bmalloc/ChangeLog b/Source/bmalloc/ChangeLog
index 578648e..b0386b3 100644
--- a/Source/bmalloc/ChangeLog
+++ b/Source/bmalloc/ChangeLog
@@ -1,3 +1,13 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        * Configurations/DebugRelease.xcconfig: Removed definition of MACOSX_DEPLOYMENT_TARGET for
+          OS X 10.9.
+
 2015-12-03  Anders Carlsson  <andersca@apple.com>
 
         Remove Objective-C GC support
diff --git a/Source/bmalloc/Configurations/DebugRelease.xcconfig b/Source/bmalloc/Configurations/DebugRelease.xcconfig
index f89fd79..c0b9a1a 100644
--- a/Source/bmalloc/Configurations/DebugRelease.xcconfig
+++ b/Source/bmalloc/Configurations/DebugRelease.xcconfig
@@ -27,7 +27,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(PLATFORM_NAME)_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-MACOSX_DEPLOYMENT_TARGET_macosx_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_macosx_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_macosx_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_macosx_101200 = 10.12;
diff --git a/Tools/ChangeLog b/Tools/ChangeLog
index 67508ff..3eff2d1 100644
--- a/Tools/ChangeLog
+++ b/Tools/ChangeLog
@@ -1,3 +1,27 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        - Removed definitions of MACOSX_DEPLOYMENT_TARGET and WEBKIT_SYSTEM_INTERFACE_LIBRARY for
+          OS X 10.9:
+
+        * DumpRenderTree/mac/Configurations/DebugRelease.xcconfig:
+        * LayoutTestRelay/Configurations/DebugRelease.xcconfig:
+        * MiniBrowser/Configurations/DebugRelease.xcconfig:
+        * TestWebKitAPI/Configurations/DebugRelease.xcconfig:
+        * WebKitTestRunner/Configurations/DebugRelease.xcconfig:
+
+        - Simplified expressions involving __MAC_OS_X_VERSION_MIN_REQUIRED and removed code that was
+          never getting compiled:
+
+        * DumpRenderTree/mac/TextInputController.m:
+        * MiniBrowser/mac/BrowserWindowController.m:
+        * TestWebKitAPI/Tests/mac/AttributedString.mm:
+        * WebKitTestRunner/mac/EventSenderProxy.mm:
+
 2015-12-18  Michael Catanzaro  <mcatanzaro@igalia.com>
 
         Unreviewed, add WebKitGTK+ Bugzilla email to committers list
diff --git a/Tools/DumpRenderTree/mac/Configurations/DebugRelease.xcconfig b/Tools/DumpRenderTree/mac/Configurations/DebugRelease.xcconfig
index 027a7d2..2a9da81 100644
--- a/Tools/DumpRenderTree/mac/Configurations/DebugRelease.xcconfig
+++ b/Tools/DumpRenderTree/mac/Configurations/DebugRelease.xcconfig
@@ -28,13 +28,11 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET[sdk=macosx*] = $(MACOSX_DEPLOYMENT_TARGET_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-MACOSX_DEPLOYMENT_TARGET_macosx_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_macosx_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_macosx_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_macosx_101200 = 10.12;
 
 WEBKIT_SYSTEM_INTERFACE_LIBRARY[sdk=macosx*] = $(WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_1090 = WebKitSystemInterfaceMavericks;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101000 = WebKitSystemInterfaceYosemite;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101100 = WebKitSystemInterfaceElCapitan;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101200 = $(WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101100);
diff --git a/Tools/DumpRenderTree/mac/TextInputController.m b/Tools/DumpRenderTree/mac/TextInputController.m
index 3901daa..5ec2a99 100644
--- a/Tools/DumpRenderTree/mac/TextInputController.m
+++ b/Tools/DumpRenderTree/mac/TextInputController.m
@@ -36,14 +36,12 @@
 #import <AppKit/NSInputManager.h>
 #import <AppKit/NSTextAlternatives.h>
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 #define SUPPORT_INSERTION_UNDO_GROUPING
 #if __has_include(<AppKit/NSTextInputContext_Private.h>)
 #import <AppKit/NSTextInputContext_Private.h>
 #else
 NSString *NSTextInsertionUndoableAttributeName;
 #endif
-#endif
 
 #import <WebKit/WebDocument.h>
 #import <WebKit/WebFrame.h>
diff --git a/Tools/LayoutTestRelay/Configurations/DebugRelease.xcconfig b/Tools/LayoutTestRelay/Configurations/DebugRelease.xcconfig
index 2b98928..0262e22 100644
--- a/Tools/LayoutTestRelay/Configurations/DebugRelease.xcconfig
+++ b/Tools/LayoutTestRelay/Configurations/DebugRelease.xcconfig
@@ -26,7 +26,6 @@
 ARCHS = $(ARCHS_STANDARD_64_BIT);
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-MACOSX_DEPLOYMENT_TARGET_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_101200 = 10.12;
diff --git a/Tools/MiniBrowser/Configurations/DebugRelease.xcconfig b/Tools/MiniBrowser/Configurations/DebugRelease.xcconfig
index cfb526e..1c65f88 100644
--- a/Tools/MiniBrowser/Configurations/DebugRelease.xcconfig
+++ b/Tools/MiniBrowser/Configurations/DebugRelease.xcconfig
@@ -28,7 +28,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-MACOSX_DEPLOYMENT_TARGET_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_101200 = 10.12;
diff --git a/Tools/MiniBrowser/mac/BrowserWindowController.m b/Tools/MiniBrowser/mac/BrowserWindowController.m
index a069cd9..3701cb7 100644
--- a/Tools/MiniBrowser/mac/BrowserWindowController.m
+++ b/Tools/MiniBrowser/mac/BrowserWindowController.m
@@ -39,9 +39,7 @@
 
 - (void)windowDidLoad
 {
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     self.window.styleMask |= NSFullSizeContentViewWindowMask;
-#endif
 
     [super windowDidLoad];
 }
diff --git a/Tools/TestWebKitAPI/Configurations/DebugRelease.xcconfig b/Tools/TestWebKitAPI/Configurations/DebugRelease.xcconfig
index a8836d6..ecb10d4 100644
--- a/Tools/TestWebKitAPI/Configurations/DebugRelease.xcconfig
+++ b/Tools/TestWebKitAPI/Configurations/DebugRelease.xcconfig
@@ -28,7 +28,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-MACOSX_DEPLOYMENT_TARGET_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_101200 = 10.12;
diff --git a/Tools/TestWebKitAPI/Tests/mac/AttributedString.mm b/Tools/TestWebKitAPI/Tests/mac/AttributedString.mm
index fe5ea5c..f7fbd95 100644
--- a/Tools/TestWebKitAPI/Tests/mac/AttributedString.mm
+++ b/Tools/TestWebKitAPI/Tests/mac/AttributedString.mm
@@ -38,26 +38,14 @@
     return [(NSView <NSTextInput> *)[[[webView mainFrame] frameView] documentView] attributedSubstringFromRange:range];
 }
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090
-static NSAttributedString *attributedString(WKView *wkView, NSRange range)
-{
-    NSRange actualRange;
-    return [wkView attributedSubstringForProposedRange:range actualRange:&actualRange];
-}
-#endif
-
 class AttributedStringTest_CustomFont : public WebKitAgnosticTest {
 public:
     template <typename View> void runSyncTest(View);
 
     // WebKitAgnosticTest
     virtual void didLoadURL(WebView *webView) { runSyncTest(webView); }
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090
-    virtual void didLoadURL(WKView *wkView) { runSyncTest(wkView); }
-#else
     // FIXME: Reimplement the test using async NSTextInputClient interface.
     virtual void didLoadURL(WKView *wkView) { }
-#endif
 
     virtual NSURL *url() const { return [[NSBundle mainBundle] URLForResource:@"attributedStringCustomFont" withExtension:@"html" subdirectory:@"TestWebKitAPI.resources"]; }
 };
@@ -74,25 +62,14 @@
     runWebKit1Test();
 }
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090
-TEST_F(AttributedStringTest_CustomFont, WebKit2)
-{
-    runWebKit2Test();
-}
-#endif
-
 class AttributedStringTest_Strikethrough : public WebKitAgnosticTest {
 public:
     template <typename View> void runSyncTest(View);
 
     // WebKitAgnosticTest
     virtual void didLoadURL(WebView *webView) { runSyncTest(webView); }
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090
-    virtual void didLoadURL(WKView *wkView) { runSyncTest(wkView); }
-#else
     // FIXME: Reimplement the test using async NSTextInputClient interface.
     virtual void didLoadURL(WKView *wkView) { }
-#endif
 
     virtual NSURL *url() const { return [[NSBundle mainBundle] URLForResource:@"attributedStringStrikethrough" withExtension:@"html" subdirectory:@"TestWebKitAPI.resources"]; }
 };
@@ -115,11 +92,4 @@
     runWebKit1Test();
 }
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED <= 1090
-TEST_F(AttributedStringTest_Strikethrough, WebKit2)
-{
-    runWebKit2Test();
-}
-#endif
-
 } // namespace TestWebKitAPI
diff --git a/Tools/WebKitTestRunner/Configurations/DebugRelease.xcconfig b/Tools/WebKitTestRunner/Configurations/DebugRelease.xcconfig
index ff5c490..cff2ed6 100644
--- a/Tools/WebKitTestRunner/Configurations/DebugRelease.xcconfig
+++ b/Tools/WebKitTestRunner/Configurations/DebugRelease.xcconfig
@@ -28,7 +28,6 @@
 ONLY_ACTIVE_ARCH = YES;
 
 MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(TARGET_MAC_OS_X_VERSION_MAJOR))
-MACOSX_DEPLOYMENT_TARGET_1090 = 10.9;
 MACOSX_DEPLOYMENT_TARGET_101000 = 10.10;
 MACOSX_DEPLOYMENT_TARGET_101100 = 10.11;
 MACOSX_DEPLOYMENT_TARGET_101200 = 10.12;
@@ -36,7 +35,6 @@
 WEBKIT_SYSTEM_INTERFACE_LIBRARY[sdk=iphoneos*] = WebKitSystemInterfaceIOSDevice$(IPHONEOS_DEPLOYMENT_TARGET);
 WEBKIT_SYSTEM_INTERFACE_LIBRARY[sdk=iphonesimulator*] = WebKitSystemInterfaceIOSSimulator$(IPHONEOS_DEPLOYMENT_TARGET);
 WEBKIT_SYSTEM_INTERFACE_LIBRARY[sdk=macosx*] = $(WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_$(TARGET_MAC_OS_X_VERSION_MAJOR));
-WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_1090 = WebKitSystemInterfaceMavericks;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101000 = WebKitSystemInterfaceYosemite;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101100 = WebKitSystemInterfaceElCapitan;
 WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101200 = $(WEBKIT_SYSTEM_INTERFACE_LIBRARY_macosx_101100);
diff --git a/Tools/WebKitTestRunner/mac/EventSenderProxy.mm b/Tools/WebKitTestRunner/mac/EventSenderProxy.mm
index a5e665b..19b5a37 100644
--- a/Tools/WebKitTestRunner/mac/EventSenderProxy.mm
+++ b/Tools/WebKitTestRunner/mac/EventSenderProxy.mm
@@ -46,7 +46,6 @@
 @end
 
 #if defined(__LP64__)
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 struct WKTRCGSEventRecord {
     char offset1[150];
     uint8_t phase;
@@ -55,16 +54,6 @@
     float deltaY;
     char offset3[76];
 } __attribute__((packed));
-#else
-struct WKTRCGSEventRecord {
-    char offset1[154];
-    uint8_t phase;
-    char offset2[5];
-    float deltaX;
-    float deltaY;
-    char offset3[80];
-} __attribute__((packed));
-#endif
 #endif
 
 @interface EventSenderSyntheticEvent : NSEvent {
@@ -133,17 +122,10 @@
     return _eventSender_type;
 }
 
-#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
 - (NSEventSubtype)subtype
 {
     return (NSEventSubtype)_eventSender_subtype;
 }
-#else
-- (short)subtype
-{
-    return _eventSender_subtype;
-}
-#endif
 
 - (NSPoint)locationInWindow
 {
diff --git a/WebKitLibraries/ChangeLog b/WebKitLibraries/ChangeLog
index 9d09ca7..c9663e9 100644
--- a/WebKitLibraries/ChangeLog
+++ b/WebKitLibraries/ChangeLog
@@ -1,3 +1,12 @@
+2015-12-19  Dan Bernstein  <mitz@apple.com>
+
+        [Mac] WebKit contains dead source code for OS X Mavericks and earlier
+        https://bugs.webkit.org/show_bug.cgi?id=152462
+
+        Reviewed by Alexey Proskuryakov.
+
+        * libWebKitSystemInterfaceMavericks.a: Removed.
+
 2015-12-16  Youenn Fablet  <youenn.fablet@crf.canon.fr>
 
         [Fetch API] Add fetch API compile time flag
diff --git a/WebKitLibraries/libWebKitSystemInterfaceMavericks.a b/WebKitLibraries/libWebKitSystemInterfaceMavericks.a
deleted file mode 100644
index a24f3fb..0000000
--- a/WebKitLibraries/libWebKitSystemInterfaceMavericks.a
+++ /dev/null
Binary files differ