Add initial implementation of date-time-settings MD settings page.

chrome/browser/resources/settings/prefs/prefs.js

Index: chrome/browser/resources/settings/prefs/prefs.js
diff --git a/chrome/browser/resources/settings/prefs/prefs.js b/chrome/browser/resources/settings/prefs/prefs.js
index f7491d903962c6ff7c592585f6f82964f4639315..602d2a54267f61b8df2a610e2c08bbba4fb3d9d1 100644
--- a/chrome/browser/resources/settings/prefs/prefs.js
+++ b/chrome/browser/resources/settings/prefs/prefs.js
@@ -39,6 +39,7 @@
    * @const {!Array<string>}
    */
   var CROS_ONLY_PREFS = [
+    'cros.system.timezone',
     'settings.accessibility',
     'settings.a11y.autoclick',
     'settings.a11y.autoclick_delay_ms',
@@ -48,6 +49,7 @@
     'settings.a11y.screen_magnifier',
     'settings.a11y.sticky_keys_enabled',
     'settings.a11y.virtual_keyboard',
+    'settings.settings.clock.use_24Hour_Clock',
     'settings.touchpad.enable_tap_dragging',
   ];