[Presentation API] Change ListenForSessionMessages API to client-style.

chrome/browser/media/android/router/media_router_android.h

 // Copyright 2015 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_ANDROID_ROUTER_MEDIA_ROUTER_ANDROID_H_
 #define CHROME_BROWSER_MEDIA_ANDROID_ROUTER_MEDIA_ROUTER_ANDROID_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/media/router/media_router.h"
 
@@ skipping 22 matching lines @@
       int tab_id,
       const std::vector<MediaRouteResponseCallback>& callbacks) override;
   void CloseRoute(const MediaRoute::Id& route_id) override;
   void SendRouteMessage(const MediaRoute::Id& route_id,
                         const std::string& message,
                         const SendRouteMessageCallback& callback) override;
   void SendRouteBinaryMessage(
       const MediaRoute::Id& route_id,
       scoped_ptr<std::vector<uint8>> data,
       const SendRouteMessageCallback& callback) override;
-  void ListenForRouteMessages(
-      const std::vector<MediaRoute::Id>& route_ids,
-      const PresentationSessionMessageCallback& message_cb) override;
   void ClearIssue(const Issue::Id& issue_id) override;
 
  private:
   friend class MediaRouterFactory;
 
   explicit MediaRouterAndroid(content::BrowserContext*);
 
   // MediaRouter implementation.
   void RegisterMediaSinksObserver(MediaSinksObserver* observer) override;
   void UnregisterMediaSinksObserver(MediaSinksObserver* observer) override;
   void RegisterMediaRoutesObserver(MediaRoutesObserver* observer) override;
   void UnregisterMediaRoutesObserver(MediaRoutesObserver* observer) override;
   void RegisterIssuesObserver(IssuesObserver* observer) override;
   void UnregisterIssuesObserver(IssuesObserver* observer) override;
+  void RegisterPresentationSessionMessagesObserver(
+      PresentationSessionMessagesObserver* observer) override;
+  void UnregisterPresentationSessionMessagesObserver(
+      PresentationSessionMessagesObserver* observer) override;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterAndroid);
 };
 
 } // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ANDROID_ROUTER_MEDIA_ROUTER_ANDROID_H_