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

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

Index: chrome/browser/media/android/router/media_router_android.h
diff --git a/chrome/browser/media/android/router/media_router_android.h b/chrome/browser/media/android/router/media_router_android.h
index f8aa6fb55802b719a92c5a165d2be5fcdcff1099..eb14600317b6b11351472d6e9a1e71c39ba798e3 100644
--- a/chrome/browser/media/android/router/media_router_android.h
+++ b/chrome/browser/media/android/router/media_router_android.h
@@ -40,9 +40,6 @@ class MediaRouterAndroid : public MediaRouter {
       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:
@@ -57,6 +54,10 @@ class MediaRouterAndroid : public MediaRouter {
   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);
 };