Media Related changes for TabCapture API

chrome/browser/media/media_internals_observer.h

 // Copyright (c) 2011 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 CHROME_BROWSER_MEDIA_MEDIA_INTERNALS_OBSERVER_H_
 #define CHROME_BROWSER_MEDIA_MEDIA_INTERNALS_OBSERVER_H_
 
+#include "content/public/common/media_stream_request.h"
+
 // Used by MediaInternalsUI to receive callbacks on media events.
 // Callbacks will be on the IO thread.
 class MediaInternalsObserver {
  public:
   // Handle an information update consisting of a javascript function call.
-  virtual void OnUpdate(const string16& javascript) = 0;
+  virtual void OnUpdate(const string16& javascript) {}
+
+  // Handle an information update related to a media stream request.
+  virtual void OnRequestUpdate(
+      const content::MediaStreamDevice& device,
+      const content::MediaStreamRequest::RequestState state) {}
+
   virtual ~MediaInternalsObserver() {}
 };
 
 #endif  // CHROME_BROWSER_MEDIA_MEDIA_INTERNALS_OBSERVER_H_