Make cc output surface creation async

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 bb59e434e6ede243fde0d88c3860b5bf760e39d3..abfa06c7d556123efb397b7e591326e72503415a 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -291,9 +291,8 @@ class LayerTreeHostClientForTesting : public LayerTreeHostClient,
     test_hooks_->ApplyScrollAndScale(scroll_delta, scale);
   }
 
-  virtual scoped_ptr<OutputSurface> CreateOutputSurface(bool fallback)
-      OVERRIDE {
-    return test_hooks_->CreateOutputSurface(fallback);
+  virtual void RequestNewOutputSurface(bool fallback) OVERRIDE {
+    test_hooks_->RequestNewOutputSurface(fallback);
   }
 
   virtual void DidInitializeOutputSurface() OVERRIDE {
@@ -664,6 +663,10 @@ void LayerTreeTest::RunTestWithImplSidePainting() {
   RunTest(true, false, true);
 }
 
+void LayerTreeTest::RequestNewOutputSurface(bool fallback) {
+  layer_tree_host_->SetOutputSurface(CreateOutputSurface(fallback));
+}
+
 scoped_ptr<OutputSurface> LayerTreeTest::CreateOutputSurface(bool fallback) {
   scoped_ptr<FakeOutputSurface> output_surface =
       CreateFakeOutputSurface(fallback);