Add extensions BookmarkModel observer automatically when manifest has bookmarks permission.

chrome/browser/extensions/extension_bookmarks_module.cc

 // Copyright (c) 2009 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/extension_bookmarks_module.h"
 
 #include "base/json/json_writer.h"
 #include "base/string_util.h"
 #include "chrome/browser/bookmarks/bookmark_codec.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
@@ skipping 82 matching lines @@
     int index = parent->IndexOfChild(node);
     model->Remove(parent, index);
     return true;
   }
 
  private:
   ExtensionBookmarks();
 };
 
 void BookmarksFunction::Run() {
-  // TODO(erikkay) temporary hack until adding an event listener can notify the
-  // browser.
   BookmarkModel* model = profile()->GetBookmarkModel();
   if (!model->IsLoaded()) {
     // Bookmarks are not ready yet.  We'll wait.
     registrar_.Add(this, NotificationType::BOOKMARK_MODEL_LOADED,
                    NotificationService::AllSources());
     AddRef();  // Balanced in Observe().
     return;
   }
 
-  ExtensionBookmarkEventRouter* event_router =
-      ExtensionBookmarkEventRouter::GetSingleton();
-  event_router->Observe(model);
   bool success = RunImpl();
   if (success) {
     NotificationService::current()->Notify(
         NotificationType::EXTENSION_BOOKMARKS_API_INVOKED,
         Source<const Extension>(GetExtension()),
         Details<const BookmarksFunction>(this));
   }
   SendResponse(success);
 }
 
@@ skipping 423 matching lines @@
     error_ = keys::kModifySpecialError;
     return false;
   }
   model->SetTitle(node, title);
 
   DictionaryValue* ret = ExtensionBookmarks::GetNodeDictionary(node, false);
   result_.reset(ret);
 
   return true;
 }