Remove SendBeginFramesToChildren plumbing

cc/trees/proxy_main.cc

 // Copyright 2015 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/proxy_main.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/trace_event/trace_event.h"
@@ skipping 406 matching lines @@
   {
     DebugScopedSetMainThreadBlocked main_thread_blocked(task_runner_provider_);
     CompletionEvent completion;
     channel_main_->MainFrameWillHappenOnImplForTesting(&completion,
                                                        &main_frame_will_happen);
     completion.Wait();
   }
   return main_frame_will_happen;
 }
 
-void ProxyMain::SetChildrenNeedBeginFrames(bool children_need_begin_frames) {
-  NOTREACHED() << "Only used by SingleThreadProxy";
-}
-
 void ProxyMain::SetAuthoritativeVSyncInterval(const base::TimeDelta& interval) {
   NOTREACHED() << "Only used by SingleProxyMain";
 }
 
 void ProxyMain::ReleaseOutputSurface() {
   DCHECK(IsMainThread());
   DCHECK(layer_tree_host_->output_surface_lost());
 
   DebugScopedSetMainThreadBlocked main_thread_blocked(task_runner_provider_);
   CompletionEvent completion;
@@ skipping 23 matching lines @@
     return false;
   channel_main_->SetNeedsCommitOnImpl();
   return true;
 }
 
 bool ProxyMain::IsMainThread() const {
   return task_runner_provider_->IsMainThread();
 }
 
 }  // namespace cc