Fix for https://bugs.webkit.org/show_bug.cgi?id=54991 
Scrollbar::nativeTheme()->usesOverlayScrollbars() should not be consulted for CSS 
Scrollbars
-and corresponding-
<rdar://problem/9034318>

Reviewed by Sam Weinig.

Instead of consulting the theme directly, callers should ask the Scrollbar or 
ScrollableArea if the scrollbars are overlay or not. 

* platform/ScrollView.cpp:
(WebCore::ScrollView::visibleContentRect):
(WebCore::ScrollView::scrollContents):
(WebCore::ScrollView::wheelEvent):
* platform/ScrollableArea.cpp:
(WebCore::ScrollableArea::setScrollOffsetFromAnimation):
(WebCore::ScrollableArea::hasOverlayScrollbars):
* platform/ScrollableArea.h:
* platform/Scrollbar.cpp:
(WebCore::Scrollbar::isOverlayScrollbar):
* platform/Scrollbar.h:
* rendering/RenderBox.cpp:
(WebCore::RenderBox::includeVerticalScrollbarSize):
(WebCore::RenderBox::includeHorizontalScrollbarSize):
* rendering/RenderLayer.cpp:
(WebCore::RenderLayer::verticalScrollbarWidth):
(WebCore::RenderLayer::horizontalScrollbarHeight):
* rendering/RenderListBox.cpp:
(WebCore::RenderListBox::verticalScrollbarWidth):
* rendering/RenderScrollbar.h:
(WebCore::RenderScrollbar::isOverlayScrollbar):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@79360 268f45cc-cd09-0410-ab3c-d52691b4dbfc
10 files changed