Not for review: Enable accelerated animations for orphaned layers

cc/layer_animation_controller.h

Index: cc/layer_animation_controller.h
diff --git a/cc/layer_animation_controller.h b/cc/layer_animation_controller.h
index 786887be39e9f1881479fa896df7bc5bf300b2f5..5ffe12371cd360f8ecc063786467d7f442e33972 100644
--- a/cc/layer_animation_controller.h
+++ b/cc/layer_animation_controller.h
@@ -32,6 +32,16 @@ class CC_EXPORT LayerAnimationController
     : public base::RefCounted<LayerAnimationController>,
       public LayerAnimationEventObserver {
 public:
+    // Controllers belonging to orphan layers begin in the
+    // NeverWaitedForLayout state. Once an animation is added to such
+    // a controller, it moves into the WaitingForLayout state, and then moves
+    // into the WaitedForLayout state after the next layout.
+    enum OrphanWaitStatus {
+        NeverWaitedForLayout = 0,
+        WaitingForLayout,
+        WaitedForLayout
+    };
+
     static scoped_refptr<LayerAnimationController> create(int id);
 
     int id() const { return m_id; }
@@ -77,10 +87,16 @@ public:
     void setForceSync() { m_forceSync = true; }
 
     void setAnimationRegistrar(AnimationRegistrar*);
+    AnimationRegistrar* animationRegistrar() { return m_registrar; }
 
     void addObserver(LayerAnimationValueObserver*);
     void removeObserver(LayerAnimationValueObserver*);
 
+    bool hasNonOrphanedObserver();
+
+    void setOrphanWaitStatus(OrphanWaitStatus status) { m_orphanWaitStatus = status; }
+    OrphanWaitStatus orphanWaitStatus() const { return m_orphanWaitStatus; }
+
 protected:
     friend class base::RefCounted<LayerAnimationController>;
 
@@ -123,6 +139,8 @@ private:
 
     ObserverList<LayerAnimationValueObserver> m_observers;
 
+    OrphanWaitStatus m_orphanWaitStatus;
+
     DISALLOW_COPY_AND_ASSIGN(LayerAnimationController);
 };