[Sync] Simplify GetSessionName interface

chrome/browser/sync/util/get_session_name_task.h

-// 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.
-
-#ifndef CHROME_BROWSER_SYNC_UTIL_GET_SESSION_NAME_TASK_H_
-#define CHROME_BROWSER_SYNC_UTIL_GET_SESSION_NAME_TASK_H_
-#pragma once
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/callback.h"
-#include "base/gtest_prod_util.h"
-#include "base/memory/ref_counted.h"
-
-namespace base {
-class MessageLoopProxy;
-}  // namespace base
-
-namespace browser_sync {
-
-class GetSessionNameTask
-    : public base::RefCountedThreadSafe<GetSessionNameTask> {
- public:
-  typedef base::Callback<void(const std::string& name)>
-      OnSessionNameInitialized;
-
-  explicit GetSessionNameTask(const OnSessionNameInitialized& callback);
-  virtual ~GetSessionNameTask();
-
-  void GetSessionNameAsync();
-
- private:
-  friend class base::RefCountedThreadSafe<GetSessionNameTask>;
-
-  FRIEND_TEST_ALL_PREFIXES(SyncGetSessionNameTaskTest, GetHardwareModelName);
-  FRIEND_TEST_ALL_PREFIXES(SyncGetSessionNameTaskTest, GetComputerName);
-
-  void InvokeCallback(const std::string& session_name);
-
-#if defined(OS_MACOSX)
-  // Returns the Hardware model name, without trailing numbers, if possible.
-  // See http://www.cocoadev.com/index.pl?MacintoshModels for an example list of
-  // models. If an error occurs trying to read the model, this simply returns
-  // "Unknown".
-  static std::string GetHardwareModelName();
-#endif
-
-#if defined(OS_WIN)
-  // Returns the computer name or the empty string if an error occured.
-  static std::string GetComputerName();
-#endif
-
-  const OnSessionNameInitialized callback_;
-  const scoped_refptr<base::MessageLoopProxy> thread_;
-
-  DISALLOW_COPY_AND_ASSIGN(GetSessionNameTask);
-};
-
-}  // namespace browser_sync
-
-#endif  // CHROME_BROWSER_SYNC_UTIL_GET_SESSION_NAME_TASK_H__