Blink Compositor Animation: Introduce CompositorAnimationHost correctly.

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

 /*
  * 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 177 matching lines @@
   bool userInputScrollable(ScrollbarOrientation) const override { return true; }
   bool shouldPlaceVerticalScrollbarOnLeft() const override { return false; }
   bool scrollAnimatorEnabled() const override;
   void scrollControlWasSetNeedsPaintInvalidation() override {}
   void updateScrollOffset(const ScrollOffset&, ScrollType) override;
   GraphicsLayer* layerForContainer() const override;
   GraphicsLayer* layerForScrolling() const override;
   GraphicsLayer* layerForHorizontalScrollbar() const override;
   GraphicsLayer* layerForVerticalScrollbar() const override;
   Widget* getWidget() override;
+  CompositorAnimationHost* compositorAnimationHost() const override;
   CompositorAnimationTimeline* compositorAnimationTimeline() const override;
   IntRect visibleContentRect(
       IncludeScrollbarsInRect = ExcludeScrollbars) const override;
 
   // Visual Viewport API implementation.
   double scrollLeft();
   double scrollTop();
   double clientWidth();
   double clientHeight();
   double pageScale();
@@ skipping 58 matching lines @@
   float m_scale;
   IntSize m_size;
   float m_browserControlsAdjustment;
   float m_maxPageScale;
   bool m_trackPinchZoomStatsForPage;
 };
 
 }  // namespace blink
 
 #endif  // VisualViewport_h