ChromeOS: implement per-user time zone preferences.

chrome/browser/chromeos/settings/system_settings_provider.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_CHROMEOS_SETTINGS_SYSTEM_SETTINGS_PROVIDER_H_
 #define CHROME_BROWSER_CHROMEOS_SETTINGS_SYSTEM_SETTINGS_PROVIDER_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 21 matching lines @@
   bool HandlesSetting(const std::string& path) const override;
 
   // TimezoneSettings::Observer implementation.
   void TimezoneChanged(const icu::TimeZone& timezone) override;
 
  private:
   // CrosSettingsProvider implementation.
   void DoSet(const std::string& path, const base::Value& in_value) override;
 
   std::unique_ptr<base::Value> timezone_value_;
+  std::unique_ptr<base::Value> per_user_timezone_enabled_value_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemSettingsProvider);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_SETTINGS_SYSTEM_SETTINGS_PROVIDER_H_