Break two classes defined in json_value_serializer.cc, .h into separate files.

chrome/browser/ui/webui/options/chromeos/system_options_handler.cc

 // 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.
 
 #include "chrome/browser/ui/webui/options/chromeos/system_options_handler.h"
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
-#include "base/json/json_value_serializer.h"
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
 #include "chrome/browser/chromeos/cros_settings.h"
 #include "chrome/browser/chromeos/dbus/dbus_thread_manager.h"
 #include "chrome/browser/chromeos/dbus/power_manager_client.h"
 #include "chrome/browser/chromeos/language_preferences.h"
 #include "chrome/browser/chromeos/system/input_device_settings.h"
@@ skipping 236 matching lines @@
   // can make it very difficult to see the increase brightness button.
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
       DecreaseScreenBrightness(false);
 }
 
 void SystemOptionsHandler::IncreaseScreenBrightnessCallback(
     const ListValue* args) {
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
       IncreaseScreenBrightness();
 }