Make sure we don't "hang" when the bookmarks extension API does not work. Als...

chrome/browser/dom_ui/bookmarks_ui.cc

 // Copyright (c) 2010 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/dom_ui/bookmarks_ui.h"
 
 #include "app/resource_bundle.h"
 #include "base/message_loop.h"
 #include "base/ref_counted_memory.h"
 #include "base/singleton.h"
@@ skipping 13 matching lines @@
 
 BookmarksUIHTMLSource::BookmarksUIHTMLSource()
     : DataSource(chrome::kChromeUIBookmarksHost, MessageLoop::current()) {
 }
 
 void BookmarksUIHTMLSource::StartDataRequest(const std::string& path,
                                              bool is_off_the_record,
                                              int request_id) {
   NOTREACHED() << "We should never get here since the extension should have"
                << "been triggered";
+
+  SendResponse(request_id, NULL);
 }
 
 std::string BookmarksUIHTMLSource::GetMimeType(const std::string& path) const {
-    NOTREACHED() << "We should never get here since the extension should have"
-                 << "been triggered";
+  NOTREACHED() << "We should never get here since the extension should have"
+               << "been triggered";
   return "text/html";
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 //
 // BookmarksUI
 //
 ////////////////////////////////////////////////////////////////////////////////
 
 BookmarksUI::BookmarksUI(TabContents* contents) : DOMUI(contents) {
   BookmarksUIHTMLSource* html_source = new BookmarksUIHTMLSource();
 
   // Set up the chrome://bookmarks/ source.
   ChromeThread::PostTask(
       ChromeThread::IO, FROM_HERE,
       NewRunnableMethod(
           Singleton<ChromeURLDataManager>::get(),
           &ChromeURLDataManager::AddDataSource,
           make_scoped_refptr(html_source)));
 }
 
 // static
 RefCountedMemory* BookmarksUI::GetFaviconResourceBytes() {
   return ResourceBundle::GetSharedInstance().
       LoadDataResourceBytes(IDR_BOOKMARKS_FAVICON);
 }