Made PinchViewport a ScrollableArea

Source/core/page/scrolling/ScrollingCoordinator.cpp

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 336 matching lines @@
         setupScrollbarLayer(scrollbarGraphicsLayer, scrollbarLayer, scrollLayer, containerLayer);
     } else
         removeWebScrollbarLayer(scrollableArea, orientation);
 }
 
 bool ScrollingCoordinator::scrollableAreaScrollLayerDidChange(ScrollableArea* scrollableArea)
 {
     GraphicsLayer* scrollLayer = scrollableArea->layerForScrolling();
 
     if (scrollLayer) {
-        bool isMainFrame = isForMainFrame(scrollableArea);
-        scrollLayer->setScrollableArea(scrollableArea, isMainFrame);
+        // With pinch virtual viewport we no longer need to special case the main frame.
+        bool pinchVirtualViewportEnabled = m_page->mainFrame()->document()->settings()->pinchVirtualViewportEnabled();
+        bool layerScrollShouldFireGraphicsLayerDidScroll = isForMainFrame(scrollableArea) && !pinchVirtualViewportEnabled;
+        scrollLayer->setScrollableArea(scrollableArea, layerScrollShouldFireGraphicsLayerDidScroll);
     }
 
     WebLayer* webLayer = toWebLayer(scrollableArea->layerForScrolling());
     WebLayer* containerLayer = toWebLayer(scrollableArea->layerForContainer());
     if (webLayer) {
         webLayer->setScrollClipLayer(containerLayer);
         webLayer->setScrollPosition(IntPoint(scrollableArea->scrollPosition() - scrollableArea->minimumScrollPosition()));
         webLayer->setBounds(scrollableArea->contentsSize());
         bool canScrollX = scrollableArea->userInputScrollable(HorizontalScrollbar);
         bool canScrollY = scrollableArea->userInputScrollable(VerticalScrollbar);
@@ skipping 582 matching lines @@
     bool frameIsScrollable = frameView && frameView->isScrollable();
     if (frameIsScrollable != m_wasFrameScrollable)
         return true;
 
     if (WebLayer* scrollLayer = frameView ? toWebLayer(frameView->layerForScrolling()) : 0)
         return blink::WebSize(frameView->contentsSize()) != scrollLayer->bounds();
     return false;
 }
 
 } // namespace WebCore