cc: GPU rasterize tiles synchronously in PrepareToDraw.

cc/test/layer_tree_test.cc

Index: cc/test/layer_tree_test.cc
diff --git a/cc/test/layer_tree_test.cc b/cc/test/layer_tree_test.cc
index f3f20238553d4fb5a703a2312f885058a6c8114f..8bf30ec2342c22cd9d7681a27e1ad0bdf811fc53 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -46,6 +46,11 @@ DrawResult TestHooks::PrepareToDrawOnThread(
   return draw_result;
 }
 
+scoped_ptr<Rasterizer> TestHooks::CreateRasterizer(
+    LayerTreeHostImpl* host_impl) {
+  return host_impl->LayerTreeHostImpl::CreateRasterizer();
+}
+
 void TestHooks::CreateResourceAndTileTaskWorkerPool(
     LayerTreeHostImpl* host_impl,
     scoped_ptr<TileTaskWorkerPool>* tile_task_worker_pool,
@@ -166,6 +171,10 @@ class LayerTreeHostImplForTesting : public LayerTreeHostImpl {
         block_notify_ready_to_activate_for_testing_(false),
         notify_ready_to_activate_was_blocked_(false) {}
 
+  scoped_ptr<Rasterizer> CreateRasterizer() override {
+    return test_hooks_->CreateRasterizer(this);
+  }
+
   void CreateResourceAndTileTaskWorkerPool(
       scoped_ptr<TileTaskWorkerPool>* tile_task_worker_pool,
       scoped_ptr<ResourcePool>* resource_pool,