Support single-threaded impl-side painting

cc/resources/tile_manager.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/resources/tile_manager.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 
@@ skipping 834 matching lines @@
   tiles_[tile->id()] = tile.get();
   used_layer_counts_[tile->layer_id()]++;
   return tile;
 }
 
 void TileManager::SetRasterizerForTesting(Rasterizer* rasterizer) {
   rasterizer_ = rasterizer;
   rasterizer_->SetClient(this);
 }
 
+void TileManager::WaitForTasksToFinishRunning() {
+  rasterizer_->WaitForTasksToFinishRunning();
+}
+
 bool TileManager::IsReadyToActivate() const {
   const std::vector<PictureLayerImpl*>& layers = client_->GetPictureLayers();
 
   for (std::vector<PictureLayerImpl*>::const_iterator it = layers.begin();
        it != layers.end();
        ++it) {
     if (!(*it)->AllTilesRequiredForActivationAreReadyToDraw())
       return false;
   }
 
@@ skipping 54 matching lines @@
   result -= other;
   return result;
 }
 
 bool TileManager::MemoryUsage::Exceeds(const MemoryUsage& limit) const {
   return memory_bytes_ > limit.memory_bytes_ ||
          resource_count_ > limit.resource_count_;
 }
 
 }  // namespace cc