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

content/renderer/gpu/render_widget_compositor.h

 // Copyright (c) 2013 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 CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_
 #define CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_
 
 #include "base/callback.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
@@ skipping 120 matching lines @@
   virtual void setShowScrollBottleneckRects(bool show);
   virtual void setTopControlsShownRatio(float);
 
   // TODO(aelias): Delete after Blink roll
   virtual void setTopControlsContentOffset(float);
 
   // cc::LayerTreeHostClient implementation.
   void WillBeginMainFrame() override;
   void DidBeginMainFrame() override;
   void BeginMainFrame(const cc::BeginFrameArgs& args) override;
+  void BeginMainFrameNotExpectedSoon() override;
   void Layout() override;
   void ApplyViewportDeltas(const gfx::Vector2dF& inner_delta,
                            const gfx::Vector2dF& outer_delta,
                            const gfx::Vector2dF& elastic_overscroll_delta,
                            float page_scale,
                            float top_controls_delta) override;
   void ApplyViewportDeltas(const gfx::Vector2d& scroll_delta,
                            float page_scale,
                            float top_controls_delta) override;
   void RequestNewOutputSurface() override;
@@ skipping 30 matching lines @@
   scoped_ptr<cc::LayerTreeHost> layer_tree_host_;
 
   scoped_ptr<cc::CopyOutputRequest> temporary_copy_output_request_;
 
   base::WeakPtrFactory<RenderWidgetCompositor> weak_factory_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_