cc: Remove FinishAllRendering, as it doesn't do anything anymore.

cc/trees/proxy_main.cc

Index: cc/trees/proxy_main.cc
diff --git a/cc/trees/proxy_main.cc b/cc/trees/proxy_main.cc
index 2b789944c76885aac7f8f89f6ce0d5b13e81bec0..04de28097a497ecacf39444e8f1d9bef3f04c1ee 100644
--- a/cc/trees/proxy_main.cc
+++ b/cc/trees/proxy_main.cc
@@ -260,17 +260,6 @@ void ProxyMain::BeginMainFrame(
   layer_tree_host_->DidBeginMainFrame();
 }
 
-void ProxyMain::FinishAllRendering() {
-  DCHECK(IsMainThread());
-  DCHECK(!defer_commits_);
-
-  // Make sure all GL drawing is finished on the impl thread.
-  DebugScopedSetMainThreadBlocked main_thread_blocked(task_runner_provider_);
-  CompletionEvent completion;
-  channel_main_->FinishAllRenderingOnImpl(&completion);
-  completion.Wait();
-}
-
 bool ProxyMain::IsStarted() const {
   DCHECK(IsMainThread());
   return started_;