[RemotePlayback] Keep track of source compatibility and reject prompt() correspondingly

third_party/WebKit/public/platform/modules/remoteplayback/WebRemotePlaybackClient.h

 // Copyright 2016 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 WebRemotePlaybackClient_h
 #define WebRemotePlaybackClient_h
 
 namespace blink {
 
+enum class WebRemotePlaybackAvailability;
 enum class WebRemotePlaybackState;
 
 // The interface between the HTMLMediaElement and its
 // HTMLMediaElementRemotePlayback supplement.
 class WebRemotePlaybackClient {
  public:
   virtual ~WebRemotePlaybackClient() = default;
 
   // Notifies the client that the media element state has changed.
   virtual void stateChanged(WebRemotePlaybackState) = 0;
 
   // Notifies the client of the remote playback device availability change.
-  virtual void availabilityChanged(bool availability) = 0;
+  virtual void availabilityChanged(WebRemotePlaybackAvailability) = 0;
 
   // Notifies the client that the user cancelled the prompt shown via the API.
   virtual void promptCancelled() = 0;
+
+  // Returns if the remote playback available for this media element.
+  virtual bool remotePlaybackAvailable() const = 0;
 };
 
 }  // namespace blink
 
 #endif  // WebRemotePlaybackState_h