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

content/renderer/scheduler/renderer_scheduler.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 CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_
 #define CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_
 
 #include "content/renderer/scheduler/single_thread_idle_task_runner.h"
 #include "content/renderer/scheduler/task_queue_manager.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
@@ skipping 18 matching lines @@
 
   // Returns the idle task runner. Tasks posted to this runner may be reordered
   // relative to other task types and may be starved for an arbitrarily long
   // time if no idle time is available.
   virtual scoped_refptr<SingleThreadIdleTaskRunner> IdleTaskRunner() = 0;
 
   // Returns the loading task runner.  This queue is intended for tasks related
   // to resource dispatch, foreground HTML parsing, etc...
   virtual scoped_refptr<base::SingleThreadTaskRunner> LoadingTaskRunner() = 0;
 
+  // Called to notify about the start of an extended period where no frames
+  // need to be drawn.

[Sami, 2015/02/11 15:28:25]

Could you add a note saying this needs to be called from the main thread (and a
DCHECK on the .cc side)?

[Sami, 2015/02/11 15:28:25]

Could you add a note saying this needs to be called from the main thread (and a
DCHECK on the .cc side)?

[rmcilroy, 2015/02/13 16:32:45]

Done.

+  virtual void BeginFrameNotExpectedSoon() = 0;
+
   // Called to notify about the start of a new frame.  Must be called from the
   // main thread.
   virtual void WillBeginFrame(const cc::BeginFrameArgs& args) = 0;
 
   // Called to notify that a previously begun frame was committed. Must be
   // called from the main thread.
   virtual void DidCommitFrameToCompositor() = 0;
 
   // Tells the scheduler that the system received an input event. Called by the
   // compositor (impl) thread.
@@ skipping 23 matching lines @@
   virtual void Shutdown() = 0;
 
  protected:
   RendererScheduler();
   DISALLOW_COPY_AND_ASSIGN(RendererScheduler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_