Refactor guest view availability to be API not permission based.

chrome/browser/guest_view/web_view/web_view_guest.h

 // Copyright 2014 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_GUEST_VIEW_WEB_VIEW_WEB_VIEW_GUEST_H_
 #define CHROME_BROWSER_GUEST_VIEW_WEB_VIEW_WEB_VIEW_GUEST_H_
 
 #include <vector>
 
 #include "base/observer_list.h"
@@ skipping 65 matching lines @@
   // |items| == NULL means no filtering will be applied.
   void ShowContextMenu(int request_id, const MenuItemVector* items);
 
   // Sets the frame name of the guest.
   void SetName(const std::string& name);
 
   // Set the zoom factor.
   void SetZoom(double zoom_factor);
 
   // GuestViewBase implementation.
-  virtual bool CanEmbedderUseGuestView(
-      const std::string& embedder_extension_id) OVERRIDE;
+  virtual extensions::Feature* GetFeature() OVERRIDE;
   virtual void CreateWebContents(
       const std::string& embedder_extension_id,
       int embedder_render_process_id,
       const base::DictionaryValue& create_params,
       const WebContentsCreatedCallback& callback) OVERRIDE;
   virtual void DidAttachToEmbedder() OVERRIDE;
   virtual void DidInitialize() OVERRIDE;
   virtual void DidStopLoading() OVERRIDE;
   virtual void EmbedderDestroyed() OVERRIDE;
   virtual void GuestDestroyed() OVERRIDE;
@@ skipping 292 matching lines @@
         changed(false) {}
   };
 
   typedef std::map<WebViewGuest*, NewWindowInfo> PendingWindowMap;
   PendingWindowMap pending_new_windows_;
 
   DISALLOW_COPY_AND_ASSIGN(WebViewGuest);
 };
 
 #endif  // CHROME_BROWSER_GUEST_VIEW_WEB_VIEW_WEB_VIEW_GUEST_H_