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

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

Index: chrome/browser/resources/settings/prefs/prefs_types.js
diff --git a/chrome/browser/resources/settings/prefs/prefs_types.js b/chrome/browser/resources/settings/prefs/prefs_types.js
index ce4c93bced2972581c6cc1efd6bbbbd53e066484..6108f9dfdb834f1527bc964d21acdb2dfa32acbf 100644
--- a/chrome/browser/resources/settings/prefs/prefs_types.js
+++ b/chrome/browser/resources/settings/prefs/prefs_types.js
@@ -12,6 +12,8 @@ var CrSettingsPrefs = {};
  * @typedef {{
  *   a11y: CrSettingsPrefs.A11y,
  *   touchpad: CrSettingsPrefs.Touchpad,
+ *   clock: CrSettingsPrefs.Clock,
+ *   cros: CrSettingsPrefs.CrOS,
  *   downloads: CrSettingsPrefs.Downloads,
  *   accessibility: boolean
  * }}
@@ -46,3 +48,27 @@ CrSettingsPrefs.Downloads;
  * }}
  */
 CrSettingsPrefs.Touchpad;
+
+/**
+ * @typedef {{
+ *   timezone: string
+ *   use24HourClock: boolean
+ * }}
+ */
+CrSettingsPrefs.Clock;
+
+/**
+ * Typedef matching 'cros.system'.
+ *
+ * @typedef {{
+ *   timezone: string
+ * }}
+ */
+CrSettingsPrefs.CrOSSystem;
+
+/**
+ * @typedef {{
+ *   system: CrSettingsPrefs.CrOSSystem
+ * }}
+ */
+CrSettingsPrefs.CrOS;