Reuse property trees

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index 4eb5e8173a6580bb152dec52c87a7ca359e12ab9..86296ea1e7dfeaf87d8012774d80cf1beb8bbc1a 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -55,7 +55,6 @@ class Animation;
 class AnimationDelegate;
 struct AnimationEvent;
 class CopyOutputRequest;
-class LayerAnimationDelegate;
 class LayerAnimationEventObserver;
 class LayerClient;
 class LayerImpl;
@@ -277,7 +276,8 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
   gfx::Vector2dF ScrollCompensationAdjustment() const;
 
   gfx::ScrollOffset scroll_offset() const { return scroll_offset_; }
-  void SetScrollOffsetFromImplSide(const gfx::ScrollOffset& scroll_offset);
+  void SetScrollOffsetFromImplSide(const gfx::ScrollOffset& scroll_offset,
+                                   LayerTreeHost* host);
 
   void SetScrollClipLayerId(int clip_layer_id);
   bool scrollable() const { return scroll_clip_layer_id_ != INVALID_ID; }
@@ -547,6 +547,7 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
   // knows immediately that a commit is required.  This implies SetNeedsUpdate
   // as well as SetNeedsPushProperties to push that property.
   void SetNeedsCommit();
+  void SetNeedsCommitNoRebuild();

[ajuma, 2015/04/16 14:52:14]

Please add a comment here that explains how this is different from plain
SetNeedsCommit.

   // Called when there's been a change in layer structure.  Implies both
   // SetNeedsUpdate and SetNeedsCommit, but not SetNeedsPushProperties.
   void SetNeedsFullTreeSync();