Don't destroy RenderWidgetCompositor during DoDeferredClose

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 12898df950658050255fc33a4667f3ac758d72f8..ef79496033773c29f4d3890a41cdd763e1a43d69 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -43,6 +43,7 @@ SingleThreadProxy::SingleThreadProxy(
       defer_commits_(false),
       commit_was_deferred_(false),
       commit_requested_(false),
+      host_client_finished_(false),
       weak_factory_(this) {
   TRACE_EVENT0("cc", "SingleThreadProxy::SingleThreadProxy");
   DCHECK(Proxy::IsMainThread());
@@ -97,6 +98,11 @@ void SingleThreadProxy::SetLayerTreeHostClientReady() {
   }
 }
 
+void SingleThreadProxy::SetLayerTreeHostClientFinished() {
+  DCHECK(Proxy::IsMainThread());
+  host_client_finished_ = true;
+}
+
 void SingleThreadProxy::SetVisible(bool visible) {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetVisible");
   DebugScopedSetImplThread impl(this);
@@ -113,6 +119,12 @@ void SingleThreadProxy::CreateAndInitializeOutputSurface() {
   DCHECK(Proxy::IsMainThread());
   DCHECK(layer_tree_host_->output_surface_lost());
 
+  // TODO(enne): in the future this could get handled by asynchronous
+  // output surface creation where the host client could just decline
+  // to ever create a surface when shutting down.
+  if (host_client_finished_)
+    return;
+
   scoped_ptr<OutputSurface> output_surface =
       layer_tree_host_->CreateOutputSurface();