Implement CSSOM Smooth Scroll API

Source/platform/graphics/GraphicsLayer.cpp

 /*
  * Copyright (C) 2009 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 1195 matching lines @@
     else
         m_layer->layer()->setScrollClient(this);
 }
 
 void GraphicsLayer::paint(GraphicsContext& context, const IntRect& clip)
 {
     paintGraphicsLayerContents(context, clip);
 }
 
 
-void GraphicsLayer::notifyAnimationStarted(double wallClockTime, double monotonicTime, WebAnimation::TargetProperty)
+void GraphicsLayer::notifyAnimationStarted(double wallClockTime, double monotonicTime, WebAnimation::TargetProperty targetProperty)
 {
+    if (targetProperty == WebAnimation::TargetPropertyScrollOffset) {
+        if (m_scrollableArea)
+            m_scrollableArea->notifyAnimationStarted(monotonicTime);
+        return;
+    }
+
     if (m_client)
         m_client->notifyAnimationStarted(this, wallClockTime, monotonicTime);
 }
 
-void GraphicsLayer::notifyAnimationFinished(double, double, WebAnimation::TargetProperty)
+void GraphicsLayer::notifyAnimationFinished(double wallClockTime, double monotonicTime, WebAnimation::TargetProperty targetProperty)
 {
-    // Do nothing.
+    if (targetProperty == WebAnimation::TargetPropertyScrollOffset && m_scrollableArea)
+        m_scrollableArea->notifyAnimationStarted(monotonicTime);

[Ian Vollick, 2014/02/06 16:02:31]

Hmm. This is confusing at a glance. Could you add a comment explaining why you
notifyAnimationStarted from notifyAnimationFinished? Was this supposed to be
notifyAnimationFinished?

 }
 
 void GraphicsLayer::didScroll()
 {
     if (m_scrollableArea)
         m_scrollableArea->scrollToOffsetWithoutAnimation(m_scrollableArea->minimumScrollPosition() + toIntSize(m_layer->layer()->scrollPosition()));
 }
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 void showGraphicsLayerTree(const WebCore::GraphicsLayer* layer)
 {
     if (!layer)
         return;
 
     String output = layer->layerTreeAsText(WebCore::LayerTreeIncludesDebugInfo);
     fprintf(stderr, "%s\n", output.utf8().data());
 }
 #endif