MediaRouterAction: Only observe Media Routes when there is a local route.

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

 // 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.
 
 #include "chrome/browser/media/android/router/media_router_android.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/guid.h"
 #include "base/logging.h"
@@ skipping 258 matching lines @@
     PresentationSessionMessagesObserver* observer) {
   const MediaRoute::Id& route_id = observer->route_id();
   auto* observer_list = messages_observers_.get(route_id);
   DCHECK(observer_list->HasObserver(observer));
 
   observer_list->RemoveObserver(observer);
   if (!observer_list->might_have_observers())
     messages_observers_.erase(route_id);
 }
 
+void MediaRouterAndroid::RegisterLocalMediaRoutesObserver(
+    LocalMediaRoutesObserver* observer) {
+  NOTIMPLEMENTED();
+}
+
+void MediaRouterAndroid::UnregisterLocalMediaRoutesObserver(
+    LocalMediaRoutesObserver* observer) {
+  NOTIMPLEMENTED();
+}
+
 void MediaRouterAndroid::OnSinksReceived(
     JNIEnv* env,
     jobject obj,
     jstring jsource_urn,
     jint jcount) {
   std::vector<MediaSink> sinks_converted;
   sinks_converted.reserve(jcount);
   for (int i = 0; i < jcount; ++i) {
     ScopedJavaLocalRef<jstring> jsink_urn =
         Java_ChromeMediaRouter_getSinkUrn(
@@ skipping 92 matching lines @@
   scoped_ptr<content::PresentationSessionMessage> message(
       new content::PresentationSessionMessage(content::TEXT));
   message->message = ConvertJavaStringToUTF8(env, jmessage);
   session_messages.push_back(message.Pass());
 
   FOR_EACH_OBSERVER(PresentationSessionMessagesObserver, *observer_list,
                     OnMessagesReceived(session_messages, true));
 }
 
 }  // namespace media_router