[Android] A prototype of the interactive media notification.

content/public/browser/web_contents_observer.h

 // Copyright (c) 2012 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 CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_
 
 #include "base/process/kill.h"
 #include "base/process/process_handle.h"
 #include "content/common/content_export.h"
@@ skipping 348 matching lines @@
 
   // Invoked when theme color is changed to |theme_color|.
   virtual void DidChangeThemeColor(SkColor theme_color) {}
 
   // Invoked when media is playing.
   virtual void MediaStartedPlaying() {}
 
   // Invoked when media is paused.
   virtual void MediaPaused() {}
 
+  // Invoked when media session has changed its state.
+  virtual void MediaSessionStateChanged(bool is_controllable,
+                                        bool is_suspended) {}
+
   // Invoked if an IPC message is coming from a specific RenderFrameHost.
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  RenderFrameHost* render_frame_host);
 
   // Notification that |contents| has gained focus.
   virtual void OnWebContentsFocused() {}
 
   // IPC::Listener implementation.
   bool OnMessageReceived(const IPC::Message& message) override;
 
@@ skipping 24 matching lines @@
   void ResetWebContents();
 
   WebContentsImpl* web_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_