ChromeOS: implement per-user time zone preferences.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index eccd8b051618ef2dee5c74ec856d47bdede4d19d..2e41b70922037dcd9cef3b5da3f42fe5fd4ffa7d 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -532,6 +532,9 @@ const char kTouchpadSensitivity[] = "settings.touchpad.sensitivity2";
 // A boolean pref set to true if time should be displayed in 24-hour clock.
 const char kUse24HourClock[] = "settings.clock.use_24hour_clock";
 
+// A string pref containing Timezone ID for this user.
+const char kUserTimezone[] = "settings.timezone";
+
 // This setting disables manual timezone selection and starts periodic timezone
 // refresh.
 const char kResolveTimezoneByGeolocation[] =
@@ -1998,6 +2001,10 @@ const char kFactoryResetRequested[] = "FactoryResetRequested";
 const char kDebuggingFeaturesRequested[] = "DebuggingFeaturesRequested";
 
 #if defined(OS_CHROMEOS)
+// This setting controlls initial device timezone that is used before user
+// session started. It is controlled by device owner.
+const char kSigninScreenTimezone[] = "settings.signin_screen_timezone";
+
 // This setting starts periodic timezone refresh when not in user session.
 // (user session is controlled by user profile preference
 // kResolveTimezoneByGeolocation