cc : Make tree synchronization independent of layer tree hierarchy (2)

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1956 matching lines @@
     // to pending tree property trees.
     if (active_tree_->property_trees()->changed) {
       if (pending_tree_->property_trees()->sequence_number ==
           active_tree_->property_trees()->sequence_number)
         active_tree_->property_trees()->PushChangeTrackingTo(
             pending_tree_->property_trees());
       else
         active_tree_->root_layer()->PushLayerPropertyChangedForSubtree();
     }
 
-    std::unordered_set<LayerImpl*> layers_that_should_push_properties =
-        pending_tree_->LayersThatShouldPushProperties();
-    for (auto pending_layer : layers_that_should_push_properties) {
-      LayerImpl* active_layer = active_tree_->LayerById(pending_layer->id());
-      DCHECK(active_layer);
-      pending_layer->PushPropertiesTo(active_layer);
-    }
+    TreeSynchronizer::PushLayerProperties(pending_tree(), active_tree());
     pending_tree_->PushPropertiesTo(active_tree_.get());
     if (pending_tree_->root_layer())
       pending_tree_->property_trees()->ResetAllChangeTracking(
           PropertyTrees::ResetFlags::ALL_TREES);
 
     // Now that we've synced everything from the pending tree to the active
     // tree, rename the pending tree the recycle tree so we can reuse it on the
     // next sync.
     DCHECK(!recycle_tree_);
     pending_tree_.swap(recycle_tree_);
@@ skipping 1934 matching lines @@
   return task_runner_provider_->HasImplThread();
 }
 
 bool LayerTreeHostImpl::CommitToActiveTree() const {
   // In single threaded mode we skip the pending tree and commit directly to the
   // active tree.
   return !task_runner_provider_->HasImplThread();
 }
 
 }  // namespace cc