Revert of cc: Remove frame queuing from the scheduler. (patchset #14 id:400001 of https://coderevie…

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 8e02bb2f0ba2a01e97e8c270e8a99278a39cb505..901f3960729c2a543c0b90ee61a57cf874741628 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -292,10 +292,13 @@ void SingleThreadProxy::Stop() {
     // Take away the CompositorFrameSink before destroying things so it doesn't
     // try to call into its client mid-shutdown.
     layer_tree_host_impl_->ReleaseCompositorFrameSink();
+
+    BlockingTaskRunner::CapturePostTasks blocked(
+        task_runner_provider_->blocking_main_thread_task_runner());
     scheduler_on_impl_thread_ = nullptr;
     layer_tree_host_impl_ = nullptr;
   }
-  layer_tree_host_ = nullptr;
+  layer_tree_host_ = NULL;
 }
 
 void SingleThreadProxy::SetMutator(std::unique_ptr<LayerTreeMutator> mutator) {