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

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 <jni.h>
 
 #include "base/android/scoped_java_ref.h"
@@ skipping 73 matching lines @@
   // Notifies the media router about a message received from the media route.
   void OnMessage(
       JNIEnv* env, jobject obj, jstring jmedia_route_id, jstring jmessage);
 
  private:
   friend class MediaRouterFactory;
 
   explicit MediaRouterAndroid(content::BrowserContext*);
 
   // MediaRouter implementation.
-  void RegisterMediaSinksObserver(MediaSinksObserver* observer) override;
+  bool 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;
 
@@ skipping 34 matching lines @@
       MediaRoute::Id,
       scoped_ptr<base::ObserverList<PresentationSessionMessagesObserver>>>;
   MessagesObservers messages_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterAndroid);
 };
 
 } // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ANDROID_ROUTER_MEDIA_ROUTER_ANDROID_H_