[Presentation API] 1-UA: send message between controller and receiver page

third_party/WebKit/public/platform/modules/presentation/WebPresentationReceiver.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 WebPresentationReceiver_h
 #define WebPresentationReceiver_h
 
 #include "public/platform/WebCommon.h"
+#include "public/platform/modules/presentation/WebPresentationClient.h"
 
 namespace blink {
 
-class WebPresentationConnectionClient;
-
 // The delegate Blink provides to WebPresentationReceiverClient in order to get updates.
-class BLINK_PLATFORM_EXPORT WebPresentationReceiver {
+class BLINK_PLATFORM_EXPORT WebPresentationReceiver : public WebPresentationMessageObserver {
 public:
     virtual ~WebPresentationReceiver() = default;
 
     // Called when receiver page gets an incoming connection.
     virtual void onReceiverConnectionAvailable(WebPresentationConnectionClient*) = 0;
 };
 
 } // namespace blink
 
 #endif // WebPresentationReceiver_h