Add PointerEvent, plus feature flag, plus Web Platform Tests
https://bugs.webkit.org/show_bug.cgi?id=189867
<rdar://problem/44697384>

Reviewed by Simon Fraser.

LayoutTests/imported/w3c:

Import the Web Platform Tests for Pointer Events.

* resources/import-expectations.json:
* web-platform-tests/pointerevents/META.yml: Added.
* web-platform-tests/pointerevents/README.md: Added.
* web-platform-tests/pointerevents/extension/idlharness.window-expected.txt: Added.
* web-platform-tests/pointerevents/extension/idlharness.window.html: Added.
* web-platform-tests/pointerevents/extension/idlharness.window.js: Added.
* web-platform-tests/pointerevents/extension/pointerevent_constructor-expected.txt: Added.
* web-platform-tests/pointerevents/extension/pointerevent_constructor.html: Added.
* web-platform-tests/pointerevents/extension/pointerevent_touch-action-verification-expected.txt: Added.
* web-platform-tests/pointerevents/extension/pointerevent_touch-action-verification.html: Added.
* web-platform-tests/pointerevents/extension/w3c-import.log: Added.
* web-platform-tests/pointerevents/idlharness.window-expected.txt: Added.
* web-platform-tests/pointerevents/idlharness.window.html: Added.
* web-platform-tests/pointerevents/idlharness.window.js: Added.
* web-platform-tests/pointerevents/pointerevent_constructor-expected.txt: Added.
* web-platform-tests/pointerevents/pointerevent_constructor.html: Added.
* web-platform-tests/pointerevents/pointerevent_on_event_handlers-expected.txt: Added.
* web-platform-tests/pointerevents/pointerevent_on_event_handlers.html: Added.
* web-platform-tests/pointerevents/pointerevent_styles.css: Added.
* web-platform-tests/pointerevents/pointerevent_support.js: Added.
* web-platform-tests/pointerevents/pointerevent_touch-action-illegal-expected.txt: Added.
* web-platform-tests/pointerevents/pointerevent_touch-action-illegal.html: Added.
* web-platform-tests/pointerevents/pointerevent_touch-action-verification-expected.txt: Added.
* web-platform-tests/pointerevents/pointerevent_touch-action-verification.html: Added.
* web-platform-tests/pointerevents/pointerlock/resources/pointerevent_movementxy-iframe.html: Added.
* web-platform-tests/pointerevents/pointerlock/resources/w3c-import.log: Added.
* web-platform-tests/pointerevents/resources/pointerevent_attributes_hoverable_pointers-iframe.html: Added.
* web-platform-tests/pointerevents/resources/pointerevent_fractional_coordinates-iframe.html: Added.
* web-platform-tests/pointerevents/resources/pointerevent_pointerId_scope-iframe.html: Added.
* web-platform-tests/pointerevents/resources/w3c-import.log: Added.
* web-platform-tests/pointerevents/w3c-import.log: Added.

Source/WebCore:

Add the PointerEvent interface.

Tests: imported/w3c/web-platform-tests/pointerevents/extension/idlharness.window.html
       imported/w3c/web-platform-tests/pointerevents/extension/pointerevent_constructor.html
       imported/w3c/web-platform-tests/pointerevents/extension/pointerevent_touch-action-verification.html
       imported/w3c/web-platform-tests/pointerevents/idlharness.window.html
       imported/w3c/web-platform-tests/pointerevents/pointerevent_constructor.html
       imported/w3c/web-platform-tests/pointerevents/pointerevent_on_event_handlers.html
       imported/w3c/web-platform-tests/pointerevents/pointerevent_touch-action-illegal.html
       imported/w3c/web-platform-tests/pointerevents/pointerevent_touch-action-verification.html

* DerivedSources.make:
* Sources.txt:
* WebCore.xcodeproj/project.pbxproj:
        Add the new files.

* dom/Event.h:
(WebCore::Event::isPointerEvent const): New virtual identification method.

* dom/EventNames.in: Add PointerEvent so the InterfaceType code is generated.

* dom/PointerEvent.cpp: The PointerEvent interface, as specified by W3C.
(WebCore::PointerEvent::PointerEvent):
(WebCore::PointerEvent::eventInterface const):
* dom/PointerEvent.h: Added.
* dom/PointerEvent.idl: Added.

* page/RuntimeEnabledFeatures.h: Clean up the ordering of the features, so there aren't
confusing blank lines interspersed with #if USE macros.
(WebCore::RuntimeEnabledFeatures::setPointerEventsEnabled): Add a new flag for Pointer Events.
(WebCore::RuntimeEnabledFeatures::pointerEventsEnabled const):

Source/WebKit:

Add PointerEvents as an experimental feature.

* Shared/WebPreferences.yaml:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@236378 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/WebCore/dom/Event.h b/Source/WebCore/dom/Event.h
index bba8444..1136085 100644
--- a/Source/WebCore/dom/Event.h
+++ b/Source/WebCore/dom/Event.h
@@ -104,6 +104,7 @@
     virtual bool isInputEvent() const { return false; }
     virtual bool isKeyboardEvent() const { return false; }
     virtual bool isMouseEvent() const { return false; }
+    virtual bool isPointerEvent() const { return false; }
     virtual bool isTextEvent() const { return false; }
     virtual bool isTouchEvent() const { return false; }
     virtual bool isUIEvent() const { return false; }