Build sync engine as part of the browser build

chrome/browser/sync/util/user_settings-posix.cc

-// Copyright (c) 2009 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 entry.
-//
-// Implement the storage of service tokens in memory.
-
-#include "chrome/browser/sync/util/user_settings.h"
-
-namespace browser_sync {
-
-void UserSettings::ClearAllServiceTokens() {
-  service_tokens_.clear();
-}
-
-void UserSettings::SetAuthTokenForService(const string& email,
-    const string& service_name, const string& long_lived_service_token) {
-  service_tokens_[service_name] = long_lived_service_token;
-}
-
-bool UserSettings::GetLastUserAndServiceToken(const string& service_name,
-                                              string* username,
-                                              string* service_token) {
-  ServiceTokenMap::const_iterator iter = service_tokens_.find(service_name);
-
-  if (iter != service_tokens_.end()) {
-    *username = email_;
-    *service_token = iter->second;
-    return true;
-  }
-
-  return false;
-}
-
-}  // namespace browser_sync