[Extensions] Fix bookmark drag-and-drop bug

chrome/browser/extensions/api/bookmark_manager_private/bookmark_manager_private_api.cc

 // 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.
 
 #include "chrome/browser/extensions/api/bookmark_manager_private/bookmark_manager_private_api.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
@@ skipping 286 matching lines @@
       BookmarkTabHelper::FromWebContents(web_contents_);
   bookmark_tab_helper->set_bookmark_drag_delegate(this);
 }
 
 BookmarkManagerPrivateDragEventRouter::
     ~BookmarkManagerPrivateDragEventRouter() {
   // No need to remove ourselves as the BookmarkTabHelper's delegate, since they
   // are both WebContentsUserData and will be deleted at the same time.
 }
 
-void BookmarkManagerPrivateDragEventRouter::MaybeCreateForWebContents(
-    content::WebContents* web_contents) {
-  content::BrowserContext* context = web_contents->GetBrowserContext();
-  const Extension* extension =
-      ExtensionRegistry::Get(context)
-          ->enabled_extensions()
-          .GetExtensionOrAppByURL(
-              web_contents->GetSiteInstance()->GetSiteURL());
-  if (extension && extension->id() == extension_misc::kBookmarkManagerId)
-    CreateForWebContents(web_contents);
-}
-
 void BookmarkManagerPrivateDragEventRouter::DispatchEvent(
     events::HistogramValue histogram_value,
     const std::string& event_name,
     std::unique_ptr<base::ListValue> args) {
   EventRouter* event_router = EventRouter::Get(profile_);
   if (!event_router)
     return;
 
   std::unique_ptr<Event> event(
       new Event(histogram_value, event_name, std::move(args)));
@@ skipping 543 matching lines @@
 
   RedoInfo::Results::Result result;
   result.enabled = undo_manager->redo_count() > 0;
   result.label = base::UTF16ToUTF8(undo_manager->GetRedoLabel());
 
   results_ = RedoInfo::Results::Create(result);
   return true;
 }
 
 }  // namespace extensions