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

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

Index: chrome/browser/media/android/router/media_router_android.cc
diff --git a/chrome/browser/media/android/router/media_router_android.cc b/chrome/browser/media/android/router/media_router_android.cc
index c1a6dbd5a46f88f9ba81b46fc6c9d1bfb3bcd476..7f7fe3dec3b7c3260a26eb040a68e676a2bab075 100644
--- a/chrome/browser/media/android/router/media_router_android.cc
+++ b/chrome/browser/media/android/router/media_router_android.cc
@@ -39,11 +39,6 @@ void MediaRouterAndroid::SendRouteMessage(
     const SendRouteMessageCallback& callback) {
   NOTIMPLEMENTED();
 }
-void MediaRouterAndroid::ListenForRouteMessages(
-    const std::vector<MediaRoute::Id>& route_ids,
-    const PresentationSessionMessageCallback& message_cb) {
-  NOTIMPLEMENTED();
-}
 void MediaRouterAndroid::ClearIssue(const Issue::Id& issue_id) {
   NOTIMPLEMENTED();
 }
@@ -70,5 +65,13 @@ void MediaRouterAndroid::RegisterIssuesObserver(IssuesObserver* observer) {
 void MediaRouterAndroid::UnregisterIssuesObserver(IssuesObserver* observer) {
   NOTIMPLEMENTED();
 }
+void MediaRouterAndroid::RegisterPresentationSessionMessagesObserver(
+    PresentationSessionMessagesObserver* observer) {
+  NOTIMPLEMENTED();
+}
+void MediaRouterAndroid::UnregisterPresentationSessionMessagesObserver(
+    PresentationSessionMessagesObserver* observer) {
+  NOTIMPLEMENTED();
+}
 
 }  // namespace media_router