Plumb an overscroll callback form the compositor to the Android UI thread.

cc/layer_tree_host_impl.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_LAYER_TREE_HOST_IMPL_H_
 #define CC_LAYER_TREE_HOST_IMPL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
@@ skipping 314 matching lines @@
 
     // In impl-side painting mode, inert tree with layers that can be recycled
     // by the next sync from the main thread.
     scoped_ptr<LayerTreeImpl> m_recycleTree;
 
     bool m_scrollDeltaIsInViewportSpace;
     LayerTreeSettings m_settings;
     LayerTreeDebugState m_debugState;
     gfx::Size m_layoutViewportSize;
     gfx::Size m_deviceViewportSize;
+    mutable gfx::Vector2dF m_pendingScrollDelta;

[aelias_OOO_until_Jul13, 2013/01/30 18:02:48]

Call this "unused" for consistency, and shouldn't be mutable.

     float m_deviceScaleFactor;
     bool m_visible;
     ManagedMemoryPolicy m_managedMemoryPolicy;
 
     bool m_pinchGestureActive;
     gfx::Point m_previousPinchAnchor;
 
     scoped_ptr<TopControlsManager> m_topControlsManager;
 
     scoped_ptr<PageScaleAnimation> m_pageScaleAnimation;
@@ skipping 19 matching lines @@
     size_t m_lastSentMemoryUseBytes;
 
     scoped_ptr<AnimationRegistrar> m_animationRegistrar;
 
     DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYER_TREE_HOST_IMPL_H_