Remove some unused linked_ptr.h includes in c/b/extensions/api

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>
 #include <utility>
 #include <vector>
 
 #include "base/lazy_instance.h"
-#include "base/memory/linked_ptr.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "chrome/browser/bookmarks/bookmark_stats.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/api/bookmarks/bookmark_api_constants.h"
 #include "chrome/browser/extensions/api/bookmarks/bookmark_api_helpers.h"
 #include "chrome/browser/extensions/extension_web_ui.h"
@@ skipping 833 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