Link MediaSessionTabHelper with native MediaSession [CL is going to be split]

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..b8d1971cc68933003411df008888909a69a41288 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -700,13 +700,6 @@ class WebContents : public PageNavigator,
   // as soon as they are ready.
   virtual void ResumeLoadingCreatedWebContents() = 0;
 
-  // Requests to resume the current media session.
-  virtual void ResumeMediaSession() = 0;
-  // Requests to suspend the current media session.
-  virtual void SuspendMediaSession() = 0;
-  // Requests to stop the current media session.
-  virtual void StopMediaSession() = 0;
-
   // Called when the WebContents has displayed a password field on an
   // HTTP page. This method modifies the appropriate NavigationEntry's
   // SSLStatus to record the sensitive input field, so that embedders