[cc]: Add a BeginMainFrameNotExpectedSoon signal and route it to the RendererScheduler.

cc/trees/layer_tree_host.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/layer_tree_host.h"
 
 #include <algorithm>
 #include <stack>
 #include <string>
 
@@ skipping 215 matching lines @@
 void LayerTreeHost::WillBeginMainFrame() {
   devtools_instrumentation::WillBeginMainThreadFrame(id(),
                                                      source_frame_number());
   client_->WillBeginMainFrame();
 }
 
 void LayerTreeHost::DidBeginMainFrame() {
   client_->DidBeginMainFrame();
 }
 
+void LayerTreeHost::BeginMainFrameNotExpectedSoon() {
+  client_->BeginMainFrameNotExpectedSoon();
+}
+
 void LayerTreeHost::BeginMainFrame(const BeginFrameArgs& args) {
   inside_begin_main_frame_ = true;
   client_->BeginMainFrame(args);
   inside_begin_main_frame_ = false;
 }
 
 void LayerTreeHost::DidStopFlinging() {
   proxy_->MainThreadHasStoppedFlinging();
 }
 
@@ skipping 1124 matching lines @@
     bool children_need_begin_frames) const {
   proxy_->SetChildrenNeedBeginFrames(children_need_begin_frames);
 }
 
 void LayerTreeHost::SendBeginFramesToChildren(
     const BeginFrameArgs& args) const {
   client_->SendBeginFramesToChildren(args);
 }
 
 }  // namespace cc