Update RootFrameViewport::userScroll to distribute scrolls between viewports.

third_party/WebKit/Source/core/frame/VisualViewport.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 405 matching lines @@
         m_pageScaleLayer->platformLayer(),
         m_innerViewportScrollLayer->platformLayer(),
         scrollLayer);
 }
 
 bool VisualViewport::visualViewportSuppliesScrollbars() const
 {
     return frameHost().settings().viewportMetaEnabled();
 }
 
+bool VisualViewport::scrollAnimatorEnabled() const
+{
+    return frameHost().settings().scrollAnimatorEnabled();
+}
+
 void VisualViewport::clearLayersForTreeView(WebLayerTreeView* layerTreeView) const
 {
     ASSERT(layerTreeView);
 
     layerTreeView->clearViewportLayers();
 }
 
 HostWindow* VisualViewport::hostWindow() const
 {
     return &frameHost().chromeClient();
@@ skipping 300 matching lines @@
     } else if (graphicsLayer == m_rootTransformLayer) {
         name =  "Root Transform Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink