CC Animation: Make ElementAnimations a ref-counted object.

cc/animation/animation_host.cc

 // 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.
 
 #include "cc/animation/animation_host.h"
 
 #include <algorithm>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
@@ skipping 188 matching lines @@
 }
 
 void AnimationHost::RemoveAnimationTimeline(
     scoped_refptr<AnimationTimeline> timeline) {
   DCHECK(timeline->id());
   EraseTimeline(timeline);
   id_to_timeline_map_.erase(timeline->id());
 }
 
 void AnimationHost::RegisterLayer(int layer_id, LayerTreeType tree_type) {
-  ElementAnimations* element_animations =
+  scoped_refptr<ElementAnimations> element_animations =
       GetElementAnimationsForLayerId(layer_id);
   if (element_animations)
     element_animations->LayerRegistered(layer_id, tree_type);
 }
 
 void AnimationHost::UnregisterLayer(int layer_id, LayerTreeType tree_type) {
-  ElementAnimations* element_animations =
+  scoped_refptr<ElementAnimations> element_animations =
       GetElementAnimationsForLayerId(layer_id);
   if (element_animations)
     element_animations->LayerUnregistered(layer_id, tree_type);
 }
 
 void AnimationHost::RegisterPlayerForLayer(int layer_id,
                                            AnimationPlayer* player) {
   DCHECK(layer_id);
   DCHECK(player);
 
-  ElementAnimations* element_animations =
+  scoped_refptr<ElementAnimations> element_animations =
       GetElementAnimationsForLayerId(layer_id);
   if (!element_animations) {
-    auto new_element_animations = ElementAnimations::Create(this);
-    element_animations = new_element_animations.get();
+    element_animations = ElementAnimations::Create(this);
+    layer_to_element_animations_map_[layer_id] = element_animations;
 
-    layer_to_element_animations_map_[layer_id] =
-        std::move(new_element_animations);
     element_animations->CreateLayerAnimationController(layer_id);
   }
 
   DCHECK(element_animations);
   element_animations->AddPlayer(player);
 }
 
 void AnimationHost::UnregisterPlayerForLayer(int layer_id,
                                              AnimationPlayer* player) {
   DCHECK(layer_id);
   DCHECK(player);
 
-  ElementAnimations* element_animations =
+  scoped_refptr<ElementAnimations> element_animations =
       GetElementAnimationsForLayerId(layer_id);
   DCHECK(element_animations);
   element_animations->RemovePlayer(player);
 
   if (element_animations->IsEmpty()) {
     element_animations->DestroyLayerAnimationController();
     layer_to_element_animations_map_.erase(layer_id);
-    element_animations = nullptr;
   }
 }
 
 void AnimationHost::SetMutatorHostClient(MutatorHostClient* client) {
   if (mutator_host_client_ == client)
     return;
 
   mutator_host_client_ = client;
 }
 
@@ skipping 48 matching lines @@
   for (auto& kv : id_to_timeline_map_) {
     AnimationTimeline* timeline = kv.second.get();
     AnimationTimeline* timeline_impl =
         host_impl->GetTimelineById(timeline->id());
     if (timeline_impl)
       timeline->PushPropertiesTo(timeline_impl);
   }
 
   // Secondly, sync properties for created layer animation controllers.
   for (auto& kv : layer_to_element_animations_map_) {
-    ElementAnimations* element_animations = kv.second.get();
-    ElementAnimations* element_animations_impl =
+    const auto& element_animations = kv.second;
+    auto element_animations_impl =
         host_impl->GetElementAnimationsForLayerId(kv.first);
     if (element_animations_impl)
-      element_animations->PushPropertiesTo(element_animations_impl);
+      element_animations->PushPropertiesTo(std::move(element_animations_impl));
   }
 }
 
 LayerAnimationController* AnimationHost::GetControllerForLayerId(
     int layer_id) const {
-  const ElementAnimations* element_animations =
+  const scoped_refptr<ElementAnimations> element_animations =
       GetElementAnimationsForLayerId(layer_id);
   if (!element_animations)
     return nullptr;
 
   return element_animations->layer_animation_controller_.get();
 }
 
-ElementAnimations* AnimationHost::GetElementAnimationsForLayerId(
+scoped_refptr<ElementAnimations> AnimationHost::GetElementAnimationsForLayerId(
     int layer_id) const {
   DCHECK(layer_id);
   auto iter = layer_to_element_animations_map_.find(layer_id);
   return iter == layer_to_element_animations_map_.end() ? nullptr
-                                                        : iter->second.get();
+                                                        : iter->second;
 }
 
 void AnimationHost::SetSupportsScrollAnimations(
     bool supports_scroll_animations) {
   supports_scroll_animations_ = supports_scroll_animations;
 }
 
 bool AnimationHost::SupportsScrollAnimations() const {
   return supports_scroll_animations_;
 }
@@ skipping 349 matching lines @@
 AnimationHost::active_animation_controllers_for_testing() const {
   return active_animation_controllers_;
 }
 
 const AnimationHost::AnimationControllerMap&
 AnimationHost::all_animation_controllers_for_testing() const {
   return all_animation_controllers_;
 }
 
 }  // namespace cc