cc: Tell scheduler the output surface is lost before releasing it.

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 0d7e4eee11ebce067fa9468ecb944b1dbde05b4f..f69296deb1bb8fdc9540b48093639cc3ccc68720 100644
--- a/cc/trees/proxy_impl.cc
+++ b/cc/trees/proxy_impl.cc
@@ -117,6 +117,7 @@ ProxyImpl::~ProxyImpl() {
 
   // Take away the OutputSurface before destroying things so it doesn't try
   // to call into its client mid-shutdown.
+  scheduler_->DidLoseOutputSurface();
   layer_tree_host_impl_->ReleaseOutputSurface();
 
   scheduler_ = nullptr;