cc: Defer first OutputSurface creation until client is ready

cc/trees/single_thread_proxy.cc

Index: cc/trees/single_thread_proxy.cc
diff --git a/cc/trees/single_thread_proxy.cc b/cc/trees/single_thread_proxy.cc
index ee6d2fd3cfbdf117b3b2015708636d12b996578e..36441d648fef3eb03979b36627fd09cbfca62b08 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -44,11 +44,9 @@ SingleThreadProxy::SingleThreadProxy(LayerTreeHost* layer_tree_host,
       << "Threaded compositing must be enabled to use impl-side painting.";
 }
 
-void SingleThreadProxy::Start(scoped_ptr<OutputSurface> first_output_surface) {
-  DCHECK(first_output_surface);
+void SingleThreadProxy::Start() {
   DebugScopedSetImplThread impl(this);
   layer_tree_host_impl_ = layer_tree_host_->CreateLayerTreeHostImpl(this);
-  first_output_surface_ = first_output_surface.Pass();
 }
 
 SingleThreadProxy::~SingleThreadProxy() {
@@ -95,9 +93,10 @@ bool SingleThreadProxy::IsStarted() const {
   return layer_tree_host_impl_;
 }
 
-void SingleThreadProxy::SetLayerTreeHostClientReady() {
-  // Scheduling is controlled by the embedder in the single thread case, so
-  // nothing to do.
+void SingleThreadProxy::SetLayerTreeHostClientReady(
+    scoped_ptr<OutputSurface> first_output_surface) {
+  DCHECK(first_output_surface);
+  first_output_surface_ = first_output_surface.Pass();
 }
 
 void SingleThreadProxy::SetVisible(bool visible) {