Use an auxiliary list of animation controllers.

cc/layer_impl.h

Index: cc/layer_impl.h
diff --git a/cc/layer_impl.h b/cc/layer_impl.h
index 6cc4d1230b349846c3fb0495fe19e317372a1aa4..7e91e404180e213337783620e7cb647fb6ca6bbb 100644
--- a/cc/layer_impl.h
+++ b/cc/layer_impl.h
@@ -36,7 +36,7 @@ class Layer;
 
 struct AppendQuadsData;
 
-class CC_EXPORT LayerImpl : public LayerAnimationControllerClient {
+class CC_EXPORT LayerImpl {
 public:
     static scoped_ptr<LayerImpl> create(int id)
     {
@@ -45,12 +45,7 @@ public:
 
     virtual ~LayerImpl();
 
-    // LayerAnimationControllerClient implementation.
-    virtual int id() const OVERRIDE;
-    virtual void setOpacityFromAnimation(float) OVERRIDE;
-    virtual float opacity() const OVERRIDE;
-    virtual void setTransformFromAnimation(const gfx::Transform&) OVERRIDE;
-    virtual const gfx::Transform& transform() const OVERRIDE;
+    int id() const;
 
     // Tree structure.
     LayerImpl* parent() { return m_parent; }
@@ -73,7 +68,7 @@ public:
     bool replicaHasMask() const { return m_replicaLayer && (m_maskLayer || m_replicaLayer->m_maskLayer); }
 
     LayerTreeHostImpl* layerTreeHostImpl() const { return m_layerTreeHostImpl; }
-    void setLayerTreeHostImpl(LayerTreeHostImpl* hostImpl) { m_layerTreeHostImpl = hostImpl; }
+    void setLayerTreeHostImpl(LayerTreeHostImpl* hostImpl);
 
     scoped_ptr<SharedQuadState> createSharedQuadState() const;
     // willDraw must be called before appendQuads. If willDraw is called,
@@ -125,6 +120,7 @@ public:
     bool contentsOpaque() const { return m_contentsOpaque; }
 
     void setOpacity(float);
+    float opacity() const;
     bool opacityIsAnimating() const;
 
     void setPosition(const gfx::PointF&);
@@ -229,6 +225,7 @@ public:
     void setDoubleSided(bool);
 
     void setTransform(const gfx::Transform&);
+    const gfx::Transform& transform() const;
     bool transformIsAnimating() const;
 
     const gfx::Transform& drawTransform() const { return m_drawTransform; }
@@ -355,12 +352,14 @@ private:
     bool m_masksToBounds;
     bool m_contentsOpaque;
     float m_opacity;
+    base::TimeTicks m_opacityLastUpdateTime;
     gfx::PointF m_position;
     bool m_preserves3D;
     bool m_useParentBackfaceVisibility;
     bool m_drawCheckerboardForMissingTiles;
     gfx::Transform m_sublayerTransform;
     gfx::Transform m_transform;
+    base::TimeTicks m_transformLastUpdateTime;
     bool m_useLCDText;
 
     bool m_drawsContent;
@@ -420,7 +419,7 @@ private:
     gfx::RectF m_updateRect;
 
     // Manages animations for this layer.
-    scoped_ptr<LayerAnimationController> m_layerAnimationController;
+    scoped_refptr<LayerAnimationController> m_layerAnimationController;
 
     // Manages scrollbars for this layer
     scoped_ptr<ScrollbarAnimationController> m_scrollbarAnimationController;