Make SingleThreadProxy a SchedulerClient

cc/trees/thread_proxy.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/thread_proxy.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/auto_reset.h"
@@ skipping 447 matching lines @@
 }
 
 void ThreadProxy::SetNextCommitWaitsForActivation() {
   DCHECK(IsMainThread());
   DCHECK(!blocked_main().main_thread_inside_commit);
   blocked_main().commit_waits_for_activation = true;
 }
 
 void ThreadProxy::SetDeferCommits(bool defer_commits) {
   DCHECK(IsMainThread());
-  DCHECK_NE(main().defer_commits, defer_commits);
+  if (main().defer_commits == defer_commits)
+    return;
+
   main().defer_commits = defer_commits;
-
   if (main().defer_commits)
     TRACE_EVENT_ASYNC_BEGIN0("cc", "ThreadProxy::SetDeferCommits", this);
   else
     TRACE_EVENT_ASYNC_END0("cc", "ThreadProxy::SetDeferCommits", this);
 
   if (!main().defer_commits && main().pending_deferred_commit) {
     Proxy::MainThreadTaskRunner()->PostTask(
         FROM_HERE,
         base::Bind(&ThreadProxy::BeginMainFrame,
                    main_thread_weak_ptr_,
@@ skipping 956 matching lines @@
 
   impl().timing_history.DidActivateSyncTree();
 }
 
 void ThreadProxy::DidManageTiles() {
   DCHECK(IsImplThread());
   impl().scheduler->DidManageTiles();
 }
 
 }  // namespace cc