Move chrome/browser/chromeos/drive/file_system.cc (+deps) into components/drive.

chrome/browser/chromeos/drive/dummy_file_system.cc

-// Copyright 2014 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/chromeos/drive/dummy_file_system.h"
-
-namespace drive {
-
-base::Closure DummyFileSystem::GetFileContent(
-      const base::FilePath& file_path,
-      const GetFileContentInitializedCallback& initialized_callback,
-      const google_apis::GetContentCallback& get_content_callback,
-      const FileOperationCallback& completion_callback) {
-  return base::Bind(&base::DoNothing);
-}
-
-}  // namespace drive