cc: Setup API to release OutputSurface from LTHClient.

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 8193758812327d2bd2408cdedd8c5fa6a9335665..e0d9d967fd733c6d8bea35325e37f2771da71c0d 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -149,6 +149,12 @@ void SingleThreadProxy::RequestNewOutputSurface() {
   layer_tree_host_->RequestNewOutputSurface();
 }
 
+scoped_ptr<OutputSurface> SingleThreadProxy::ReleaseOutputSurface() {
+  if (scheduler_on_impl_thread_)
+    scheduler_on_impl_thread_->DidLoseOutputSurface();
+  return layer_tree_host_impl_->ReleaseOutputSurface();
+}
+
 void SingleThreadProxy::SetOutputSurface(
     scoped_ptr<OutputSurface> output_surface) {
   DCHECK(Proxy::IsMainThread());