CC Animation: Activate/deactivate ElementAnimations on Layer addition/removal.

cc/animation/element_animations.h

 // Copyright 2015 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_ANIMATION_ELEMENT_ANIMATIONS_H_
 #define CC_ANIMATION_ELEMENT_ANIMATIONS_H_
 
 #include <bitset>
 #include <memory>
 #include <vector>
@@ skipping 107 matching lines @@
   void NotifyAnimationAborted(const AnimationEvent& event);
   void NotifyAnimationPropertyUpdate(const AnimationEvent& event);
   void NotifyAnimationTakeover(const AnimationEvent& event);
 
   bool has_element_in_active_list() const {
     return has_element_in_active_list_;
   }
   bool has_element_in_pending_list() const {
     return has_element_in_pending_list_;
   }
+  bool has_element_in_any_list() const {
+    return has_element_in_active_list_ || has_element_in_pending_list_;
+  }
 
   void set_has_element_in_active_list(bool has_element_in_active_list) {
     has_element_in_active_list_ = has_element_in_active_list;
   }
   void set_has_element_in_pending_list(bool has_element_in_pending_list) {
     has_element_in_pending_list_ = has_element_in_pending_list;
   }
 
   bool HasFilterAnimationThatInflatesBounds() const;
   bool HasTransformAnimationThatInflatesBounds() const;
@@ skipping 155 matching lines @@
 
   struct PropertyAnimationState opacity_animation_state_;
   struct PropertyAnimationState transform_animation_state_;
 
   DISALLOW_COPY_AND_ASSIGN(ElementAnimations);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_ELEMENT_ANIMATIONS_H_