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

android_webview/browser/hardware_renderer.h

 // Copyright 2014 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 ANDROID_WEBVIEW_BROWSER_HARDWARE_RENDERER_H_
 #define ANDROID_WEBVIEW_BROWSER_HARDWARE_RENDERER_H_
 
 #include "android_webview/browser/parent_compositor_draw_constraints.h"
 #include "android_webview/browser/shared_renderer_state.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 24 matching lines @@
 
   void DrawGL(bool stencil_enabled,
               int framebuffer_binding_ext,
               AwDrawGLInfo* draw_info);
   void CommitFrame();
 
   // cc::LayerTreeHostClient overrides.
   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 47 matching lines @@
   ParentOutputSurface* output_surface_;
 
   ParentCompositorDrawConstraints draw_constraints_;
 
   DISALLOW_COPY_AND_ASSIGN(HardwareRenderer);
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_HARDWARE_RENDERER_H_