[Extensions] Remove linked_ptr entirely from extensions generated code

extensions/browser/api/system_storage/system_storage_apitest.cc

 // Copyright 2013 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 <stddef.h>
 
 #include <vector>
 
 #include "base/macros.h"
+#include "base/memory/linked_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/storage_monitor/storage_monitor.h"
 #include "components/storage_monitor/test_storage_monitor.h"
 #include "extensions/browser/api/system_storage/storage_api_test_util.h"
 #include "extensions/browser/api/system_storage/storage_info_provider.h"
 #include "extensions/shell/test/shell_apitest.h"
 #include "extensions/test/extension_test_message_listener.h"
 #include "extensions/test/result_catcher.h"
 
@@ skipping 121 matching lines @@
       removable_storage_transient_id, false);
 
   // Simulate triggering onDetached event.
   ASSERT_TRUE(detach_listener.WaitUntilSatisfied());
   DetachRemovableStorage(kRemovableStorageData.device_id);
 
   ASSERT_TRUE(detach_device_id_listener.WaitUntilSatisfied());
 
   EXPECT_TRUE(catcher.GetNextResult()) << catcher.message();
 }