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

content/renderer/scheduler/renderer_scheduler.h

Index: content/renderer/scheduler/renderer_scheduler.h
diff --git a/content/renderer/scheduler/renderer_scheduler.h b/content/renderer/scheduler/renderer_scheduler.h
index 6b4ecfaceef4fcd45bd998c5d288eed43c650371..8de1c50d22d505c28ae420e71ba8262ba8c88fbc 100644
--- a/content/renderer/scheduler/renderer_scheduler.h
+++ b/content/renderer/scheduler/renderer_scheduler.h
@@ -36,6 +36,10 @@ class CONTENT_EXPORT RendererScheduler {
   // 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;