CC Animation: Use ElementId to attach CC animation players.

cc/layers/layer_impl.cc

 // 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.
 
 #include "cc/layers/layer_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 71 matching lines @@
       current_draw_mode_(DRAW_MODE_NONE),
       element_id_(0),
       mutable_properties_(MutableProperty::kNone),
       debug_info_(nullptr),
       scrolls_drawn_descendant_(false),
       layer_or_descendant_has_touch_handler_(false) {
   DCHECK_GT(layer_id_, 0);
 
   DCHECK(layer_tree_impl_);
   layer_tree_impl_->RegisterLayer(this);
+  // TODO(loyso): Pass element_id_ via constructor.
+  // Note that since element_id_ is zero here, calling RegisterLayerForElementId
+  // and AddToElementMap is a matter of elegance/symmetry. See SetElementId.
+  if (element_id())
+    layer_tree_impl_->RegisterLayerForElementId(this);
   layer_tree_impl_->AddToElementMap(this);
 
   SetNeedsPushProperties();
 }
 
 LayerImpl::~LayerImpl() {
   DCHECK_EQ(DRAW_MODE_NONE, current_draw_mode_);
 
   if (!copy_requests_.empty() && layer_tree_impl_->IsActiveTree())
     layer_tree_impl()->RemoveLayerWithCopyOutputRequest(this);
   layer_tree_impl_->UnregisterScrollLayer(this);
-  layer_tree_impl_->UnregisterLayer(this);
-  layer_tree_impl_->RemoveLayerShouldPushProperties(this);
 
   layer_tree_impl_->RemoveFromElementMap(this);
+  if (element_id())
+    layer_tree_impl_->UnregisterLayerForElementId(this);
+  layer_tree_impl_->UnregisterLayer(this);
+
+  layer_tree_impl_->RemoveLayerShouldPushProperties(this);
 
   TRACE_EVENT_OBJECT_DELETED_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("cc.debug"), "cc::LayerImpl", this);
 
   if (mask_layer_)
     layer_tree_impl_->RemoveLayer(mask_layer_id_);
   if (replica_layer_)
     layer_tree_impl_->RemoveLayer(replica_layer_id_);
   ClearChildList();
 }
@@ skipping 265 matching lines @@
   ScrollTree& scroll_tree = layer_tree_impl()->property_trees()->scroll_tree;
   ScrollNode* scroll_node = scroll_tree.Node(scroll_tree_index());
   return scroll_tree.ScrollBy(scroll_node, scroll, layer_tree_impl());
 }
 
 void LayerImpl::SetScrollClipLayer(int scroll_clip_layer_id) {
   if (scroll_clip_layer_id_ == scroll_clip_layer_id)
     return;
 
   layer_tree_impl()->UnregisterScrollLayer(this);
+  if (element_id())
+    layer_tree_impl()->UnregisterLayerForElementId(this);
+
   scroll_clip_layer_id_ = scroll_clip_layer_id;
+
+  if (element_id())
+    layer_tree_impl()->RegisterLayerForElementId(this);
   layer_tree_impl()->RegisterScrollLayer(this);
 }
 
 LayerImpl* LayerImpl::scroll_clip_layer() const {
   return layer_tree_impl()->LayerById(scroll_clip_layer_id_);
 }
 
 bool LayerImpl::scrollable() const {
   return scroll_clip_layer_id_ != Layer::INVALID_ID;
 }
@@ skipping 613 matching lines @@
 }
 
 void LayerImpl::SetElementId(ElementId element_id) {
   if (element_id == element_id_)
     return;
 
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("compositor-worker"),
                "LayerImpl::SetElementId", "id", element_id);
 
   layer_tree_impl_->RemoveFromElementMap(this);
+  if (element_id_)
+    layer_tree_impl_->UnregisterLayerForElementId(this);
+
   element_id_ = element_id;
+
   layer_tree_impl_->AddToElementMap(this);
+  if (element_id_)
+    layer_tree_impl_->RegisterLayerForElementId(this);
+
   SetNeedsPushProperties();
 }
 
 void LayerImpl::SetMutableProperties(uint32_t properties) {
   if (mutable_properties_ == properties)
     return;
 
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("compositor-worker"),
                "LayerImpl::SetMutableProperties", "properties", properties);
 
@@ skipping 372 matching lines @@
            .layer_transforms_should_scale_layer_contents) {
     return default_scale;
   }
 
   gfx::Vector2dF transform_scales = MathUtil::ComputeTransform2dScaleComponents(
       DrawTransform(), default_scale);
   return std::max(transform_scales.x(), transform_scales.y());
 }
 
 }  // namespace cc