Remove SendBeginFramesToChildren plumbing

cc/trees/proxy_impl.h

 // 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.
 
 #ifndef CC_TREES_PROXY_IMPL_H_
 #define CC_TREES_PROXY_IMPL_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 105 matching lines @@
   void WillBeginImplFrame(const BeginFrameArgs& args) override;
   void DidFinishImplFrame() override;
   void ScheduledActionSendBeginMainFrame(const BeginFrameArgs& args) override;
   DrawResult ScheduledActionDrawAndSwapIfPossible() override;
   DrawResult ScheduledActionDrawAndSwapForced() override;
   void ScheduledActionCommit() override;
   void ScheduledActionActivateSyncTree() override;
   void ScheduledActionBeginOutputSurfaceCreation() override;
   void ScheduledActionPrepareTiles() override;
   void ScheduledActionInvalidateOutputSurface() override;
-  void SendBeginFramesToChildren(const BeginFrameArgs& args) override;
   void SendBeginMainFrameNotExpectedSoon() override;
 
   DrawResult DrawAndSwapInternal(bool forced_draw);
 
   bool IsImplThread() const;
   bool IsMainThreadBlocked() const;
 
   const int layer_tree_host_id_;
 
   std::unique_ptr<Scheduler> scheduler_;
@@ skipping 33 matching lines @@
   // Use accessors instead of this variable directly.
   BlockedMainCommitOnly main_thread_blocked_commit_vars_unsafe_;
   BlockedMainCommitOnly& blocked_main_commit();
 
   DISALLOW_COPY_AND_ASSIGN(ProxyImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_PROXY_IMPL_H_