Make tab audible and muted states and cause available for an extension API

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 665695d83390938503db2fe74338ad52b1151be5..89c00233118be88b226624758517aa8b10013a96 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -247,7 +247,7 @@ class CONTENT_EXPORT WebContentsImpl
   void DecrementCapturerCount() override;
   int GetCapturerCount() const override;
   bool IsAudioMuted() const override;
-  void SetAudioMuted(bool mute) override;
+  void SetAudioMuted(bool muted, const std::string &cause) override;

[miu, 2014/12/05 23:46:48]

style: Place the ampersand next to the type (here and throughout this change).

   bool IsCrashed() const override;
   void SetIsCrashed(base::TerminationStatus status, int error_code) override;
   base::TerminationStatus GetCrashedStatus() const override;
@@ -894,6 +894,9 @@ class CONTENT_EXPORT WebContentsImpl
   void NotifyFrameSwapped(RenderFrameHost* old_host, RenderFrameHost* new_host);
   void NotifyDisconnected();
 
+  void NotifyAudibleStateChanged(bool is_audible);
+  void NotifyMutedStateChanged(bool is_muted, const std::string& cause);
+
   void SetEncoding(const std::string& encoding);
 
   // TODO(creis): This should take in a FrameTreeNode to know which node's