Reland of cc: Remove frame queuing from the scheduler.

cc/trees/proxy_impl.cc

Index: cc/trees/proxy_impl.cc
diff --git a/cc/trees/proxy_impl.cc b/cc/trees/proxy_impl.cc
index fcefcec65949a92523e80eb9f064e82785e724cf..659ff5c9ab13a2c1fea5c57a61b620943f47858e 100644
--- a/cc/trees/proxy_impl.cc
+++ b/cc/trees/proxy_impl.cc
@@ -90,11 +90,12 @@ ProxyImpl::~ProxyImpl() {
   DCHECK(IsImplThread());
   DCHECK(IsMainThreadBlocked());
 
+  // Prevent the scheduler from performing actions while we're in an
+  // inconsistent state.
+  scheduler_->Stop();
   // Take away the CompositorFrameSink before destroying things so it doesn't
   // try to call into its client mid-shutdown.
-  scheduler_->DidLoseCompositorFrameSink();
   layer_tree_host_impl_->ReleaseCompositorFrameSink();
-
   scheduler_ = nullptr;
   layer_tree_host_impl_ = nullptr;
   // We need to explicitly shutdown the notifier to destroy any weakptrs it is