Implement unregisterProtocolHandler() for content layer

content/browser/web_contents/web_contents_impl.h

 // Copyright (c) 2012 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_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 712 matching lines @@
   void OnDidChangeLoadProgress(double load_progress);
   void OnGoToEntryAtOffset(int offset);
   void OnUpdateZoomLimits(int minimum_percent,
                           int maximum_percent);
   void OnEnumerateDirectory(int request_id, const base::FilePath& path);
 
   void OnRegisterProtocolHandler(const std::string& protocol,
                                  const GURL& url,
                                  const base::string16& title,
                                  bool user_gesture);
+  void OnUnregisterProtocolHandler(const std::string& protocol,
+                                   const GURL& url,
+                                   bool user_gesture);
   void OnFindReply(int request_id,
                    int number_of_matches,
                    const gfx::Rect& selection_rect,
                    int active_match_ordinal,
                    bool final_update);
 #if defined(OS_ANDROID)
   void OnFindMatchRectsReply(int version,
                              const std::vector<gfx::RectF>& rects,
                              const gfx::RectF& active_rect);
 
@@ skipping 412 matching lines @@
 
   scoped_ptr<ScreenOrientationDispatcherHost>
       screen_orientation_dispatcher_host_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_