Added plumbing for the availablechange event from Blink to WebPresentationClient.

public/web/WebFrameClient.h

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 57 matching lines @@
 class WebFormElement;
 class WebGeolocationClient;
 class WebMediaPlayer;
 class WebMediaPlayerClient;
 class WebMIDIClient;
 class WebNotificationPermissionCallback;
 class WebServiceWorkerProvider;
 class WebSocketHandle;
 class WebPlugin;
 class WebPluginPlaceholder;
+class WebPresentationClient;
 class WebPushClient;
 class WebRTCPeerConnectionHandler;
 class WebScreenOrientationClient;
 class WebSpeechRecognizer;
 class WebString;
 class WebURL;
 class WebURLResponse;
 class WebUserMediaClient;
 class WebWorkerPermissionClientProxy;
 struct WebColorSuggestion;
@@ skipping 238 matching lines @@
     // Requests permission to display platform notifications on the origin of this frame.
     virtual void requestNotificationPermission(const WebSecurityOrigin&, WebNotificationPermissionCallback* callback) { }
 
 
     // Push API ---------------------------------------------------
 
     // Used to access the embedder for the Push API.
     virtual WebPushClient* pushClient() { return 0; }
 
 
+    // Presentation API ----------------------------------------------------
+
+    // Used to access the embedder for the Presentation API
+    virtual WebPresentationClient* presentationClient() { return 0; }

[Peter Beverloo, 2015/01/07 14:29:09]

nit: two blank lines under here for consistency. End the comment sentence with a
period.

[whywhat, 2015/01/07 16:22:16]

Done.

+
     // Editing -------------------------------------------------------------
 
     // These methods allow the client to intercept and overrule editing
     // operations.
     virtual void didChangeSelection(bool isSelectionEmpty) { }
 
 
     // Dialogs -------------------------------------------------------------
 
     // This method opens the color chooser and returns a new WebColorChooser
@@ skipping 265 matching lines @@
     virtual bool enterFullscreen() { return false; }
     virtual bool exitFullscreen() { return false; }
 
 protected:
     virtual ~WebFrameClient() { }
 };
 
 } // namespace blink
 
 #endif