Presentation API: allow the Mojo service to reject a getAvailability() call.

content/renderer/presentation/presentation_dispatcher.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 CONTENT_RENDERER_PRESENTATION_PRESENTATION_DISPATCHER_H_
 #define CONTENT_RENDERER_PRESENTATION_PRESENTATION_DISPATCHER_H_
 
 #include "base/compiler_specific.h"
 #include "base/id_map.h"
 #include "base/memory/linked_ptr.h"
@@ skipping 56 matching lines @@
   virtual void stopListening(blink::WebPresentationAvailabilityObserver*);
 
   // RenderFrameObserver implementation.
   void DidChangeDefaultPresentation() override;
   void DidCommitProvisionalLoad(
       bool is_new_navigation,
       bool is_same_page_navigation) override;
 
   // presentation::PresentationServiceClient
   void OnScreenAvailabilityUpdated(bool available) override;
+  void OnScreenAvailabilityNotSupported() override;
 
   void OnSessionCreated(
       blink::WebPresentationSessionClientCallbacks* callback,
       presentation::PresentationSessionInfoPtr session_info,
       presentation::PresentationErrorPtr error);
   void OnDefaultSessionStarted(
       presentation::PresentationSessionInfoPtr session_info);
   void OnSessionStateChange(
       presentation::PresentationSessionInfoPtr session_info,
       presentation::PresentationSessionState session_state);
@@ skipping 33 matching lines @@
   using AvailabilityObserversSet =
       std::set<blink::WebPresentationAvailabilityObserver*>;
   AvailabilityObserversSet availability_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(PresentationDispatcher);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_PRESENTATION_PRESENTATION_DISPATCHER_H_