cc: Don't create SyncedPropety instances on the main thread.

cc/trees/layer_tree_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_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 408 matching lines @@
         inner_scroll->bounds_delta());
 }
 
 void LayerTreeImpl::PushPropertiesTo(LayerTreeImpl* target_tree) {
   // The request queue should have been processed and does not require a push.
   DCHECK_EQ(ui_resource_request_queue_.size(), 0u);
 
   LayerImpl* layer = target_tree->CurrentlyScrollingLayer();
   target_tree->SetPropertyTrees(&property_trees_);
   target_tree->SetCurrentlyScrollingLayer(layer);
-  target_tree->UpdatePropertyTreeScrollOffset(&property_trees_);
+  target_tree->property_trees()->scroll_tree.PushScrollUpdatesFromPendingTree(
+      &property_trees_, target_tree);
 
   // This needs to be called early so that we don't clamp with incorrect max
   // offsets when UpdateViewportContainerSizes is called from e.g.
   // PushBrowserControls
   target_tree->UpdatePropertyTreesForBoundsDelta();
 
   if (next_activation_forces_redraw_) {
     target_tree->ForceRedrawNextActivation();
     next_activation_forces_redraw_ = false;
   }
@@ skipping 1644 matching lines @@
 
 void LayerTreeImpl::ResetAllChangeTracking() {
   layers_that_should_push_properties_.clear();
   // Iterate over all layers, including masks.
   for (auto& layer : *layers_)
     layer->ResetChangeTracking();
   property_trees_.ResetAllChangeTracking();
 }
 
 }  // namespace cc