[Sync] Rename csync namespace to syncer

sync/util/session_utils_android.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 SYNC_UTIL_SESSION_UTILS_ANDROID_H_
 #define SYNC_UTIL_SESSION_UTILS_ANDROID_H_
 #pragma once
 
 #include <string>
 
-namespace csync {
+namespace syncer {
 namespace internal {
 
 // Return the unique identifier of this device.
 std::string GetAndroidId();
 
 // Return the end-user-visible name for this device.
 std::string GetModel();
 
 // Return if the device is a tablet.
 bool IsTabletUi();
 
 }  // namespace internal
-}  // namespace csync
+}  // namespace syncer
 
 #endif  // SYNC_UTIL_SESSION_UTILS_ANDROID_H_