Presentation API: reject screen availability observing on Android low ram devices.

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 170 matching lines @@
 
 void MediaRouterAndroid::ClearIssue(const Issue::Id& issue_id) {
   NOTIMPLEMENTED();
 }
 
 void MediaRouterAndroid::OnPresentationSessionDetached(
     const MediaRoute::Id& route_id) {
   NOTIMPLEMENTED();
 }
 
-void MediaRouterAndroid::RegisterMediaSinksObserver(
+bool MediaRouterAndroid::RegisterMediaSinksObserver(
     MediaSinksObserver* observer) {
   const std::string& source_id = observer->source().id();
   base::ObserverList<MediaSinksObserver>* observer_list =
       sinks_observers_.get(source_id);
   if (!observer_list) {
     observer_list = new base::ObserverList<MediaSinksObserver>;
     sinks_observers_.add(source_id, make_scoped_ptr(observer_list));
   } else {
     DCHECK(!observer_list->HasObserver(observer));
   }
 
   observer_list->AddObserver(observer);
   JNIEnv* env = base::android::AttachCurrentThread();
   ScopedJavaLocalRef<jstring> jsource_id =
       base::android::ConvertUTF8ToJavaString(env, source_id);
-  Java_ChromeMediaRouter_startObservingMediaSinks(
+  return Java_ChromeMediaRouter_startObservingMediaSinks(
       env, java_media_router_.obj(), jsource_id.obj());
 }
 
 void MediaRouterAndroid::UnregisterMediaSinksObserver(
     MediaSinksObserver* observer) {
   const std::string& source_id = observer->source().id();
   auto* observer_list = sinks_observers_.get(source_id);
   if (!observer_list || !observer_list->HasObserver(observer))
     return;
 
@@ skipping 163 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