CC Animation: Use ElementId to attach CC animation players.

cc/trees/layer_tree_impl.h

 // Copyright 2012 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_TREES_LAYER_TREE_IMPL_H_
 #define CC_TREES_LAYER_TREE_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 150 matching lines @@
   LayerListReverseIterator<LayerImpl> rbegin();
   LayerListReverseIterator<LayerImpl> rend();
 
   struct CC_EXPORT ElementLayers {
     // Transform and opacity mutations apply to this layer.
     LayerImpl* main = nullptr;
     // Scroll mutations apply to this layer.
     LayerImpl* scroll = nullptr;
   };
 
+  void RegisterLayerForElementId(LayerImpl* layer);
+  void UnregisterLayerForElementId(LayerImpl* layer);
   void AddToElementMap(LayerImpl* layer);
   void RemoveFromElementMap(LayerImpl* layer);
-  ElementLayers GetMutableLayers(uint64_t element_id);
+  ElementLayers GetMutableLayers(ElementId element_id);
   int source_frame_number() const { return source_frame_number_; }
   void set_source_frame_number(int frame_number) {
     source_frame_number_ = frame_number;
   }
 
   bool is_first_frame_after_commit() const {
     return source_frame_number_ != is_first_frame_after_commit_tracker_;
   }
 
   void set_is_first_frame_after_commit(bool is_first_frame_after_commit) {
@@ skipping 113 matching lines @@
   const Region& UnoccludedScreenSpaceRegion() const;
 
   // These return the size of the root scrollable area and the size of
   // the user-visible scrolling viewport, in CSS layout coordinates.
   gfx::SizeF ScrollableSize() const;
   gfx::SizeF ScrollableViewportSize() const;
 
   gfx::Rect RootScrollLayerDeviceViewportBounds() const;
 
   LayerImpl* LayerById(int id) const;
+  LayerImpl* LayerForElementId(ElementId element_id) const;
+  LayerImpl* ScrollLayerForElementId(ElementId element_id) const;
+  bool HasAnyLayerForElementId(ElementId element_id) const;
 
   void AddLayerShouldPushProperties(LayerImpl* layer);
   void RemoveLayerShouldPushProperties(LayerImpl* layer);
   std::unordered_set<LayerImpl*>& LayersThatShouldPushProperties();
   bool LayerNeedsPushPropertiesForTesting(LayerImpl* layer);
 
   // These should be called by LayerImpl's ctor/dtor.
   void RegisterLayer(LayerImpl* layer);
   void UnregisterLayer(LayerImpl* layer);
 
@@ skipping 205 matching lines @@
   float min_page_scale_factor_;
   float max_page_scale_factor_;
 
   float device_scale_factor_;
   float painted_device_scale_factor_;
 
   scoped_refptr<SyncedElasticOverscroll> elastic_overscroll_;
 
   std::unique_ptr<OwnedLayerImplList> layers_;
   LayerImplMap layer_id_map_;
+
+  using ElementIdToLayerMap = std::unordered_map<ElementId, ElementLayers>;
+  ElementIdToLayerMap element_id_to_layer_map_;
+  // TODO(loyso): Unify it with element_id_to_layer_map_.
+  std::unordered_map<ElementId, ElementLayers> element_layers_map_;
+
   // Set of layers that need to push properties.
   std::unordered_set<LayerImpl*> layers_that_should_push_properties_;
 
-  std::unordered_map<uint64_t, ElementLayers> element_layers_map_;
-
   // Maps from clip layer ids to scroll layer ids.  Note that this only includes
   // the subset of clip layers that act as scrolling containers.  (This is
   // derived from LayerImpl::scroll_clip_layer_ and exists to avoid O(n) walks.)
   std::unordered_map<int, int> clip_scroll_map_;
 
   // Maps scroll layer ids to scrollbar layer ids.  For each scroll layer, there
   // may be 1 or 2 scrollbar layers (for vertical and horizontal).  (This is
   // derived from ScrollbarLayerImplBase::scroll_layer_id_ and exists to avoid
   // O(n) walks.)
   std::multimap<int, int> scrollbar_map_;
@@ skipping 39 matching lines @@
 
   std::unique_ptr<PendingPageScaleAnimation> pending_page_scale_animation_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_IMPL_H_