Activate LayerImpl tree with sync+push instead of pointer swap

cc/picture_layer.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/picture_layer.h"
 
 #include "cc/layer_tree_impl.h"
 #include "cc/picture_layer_impl.h"
 #include "ui/gfx/rect_conversions.h"
 
@@ skipping 18 matching lines @@
 
 scoped_ptr<LayerImpl> PictureLayer::createLayerImpl(LayerTreeImpl* treeImpl) {
   return PictureLayerImpl::create(treeImpl, id()).PassAs<LayerImpl>();
 }
 
 void PictureLayer::pushPropertiesTo(LayerImpl* base_layer) {
   Layer::pushPropertiesTo(base_layer);
 
   PictureLayerImpl* layer_impl = static_cast<PictureLayerImpl*>(base_layer);
   layer_impl->SetIsMask(is_mask_);
-  layer_impl->tilings_.SetLayerBounds(bounds());
+  layer_impl->CreateTilingSet();
   layer_impl->invalidation_.Clear();
   layer_impl->invalidation_.Swap(pile_invalidation_);
   pile_->PushPropertiesTo(layer_impl->pile_);
 
   layer_impl->SyncFromActiveLayer();
 }
 
 void PictureLayer::setLayerTreeHost(LayerTreeHost* host) {
   Layer::setLayerTreeHost(host);
   if (host)
@@ skipping 23 matching lines @@
   pending_invalidation_.Clear();
 
   pile_->Update(client_, pile_invalidation_, stats);
 }
 
 void PictureLayer::setIsMask(bool is_mask) {
   is_mask_ = is_mask;
 }
 
 }  // namespace cc