[scheduler] Teach scheduler about audio state

content/public/browser/web_contents.h

Index: content/public/browser/web_contents.h
diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index 697ea3aee21d2fd89ce3a7252ce7c73c34c5797a..399c52cd1c225063fb792da5497dad2c41a06587 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -397,6 +397,9 @@ class WebContents : public PageNavigator,
   // change.
   virtual void NotifyNavigationStateChanged(InvalidateTypes changed_flags) = 0;
 
+  // Notifies the WebContents that audio started or stopped being audible.
+  virtual void OnAudioStateChanged(bool is_audio_playing) = 0;

[miu, 2016/11/15 22:04:04]

Throughout this change "playing" is inaccurate. "playing" means samples are
being delivered to the OS sound system. The audio samples may represent silent
or audible sound. So, can you please fix the naming to "audible" everywhere?

[altimin, 2016/11/16 12:22:32]

Addressed in crrev.com/2496173003

+
   // Get/Set the last time that the WebContents was made active (either when it
   // was created or shown with WasShown()).
   virtual base::TimeTicks GetLastActiveTime() const = 0;