MD Settings: Date and Time page, part 1/3

chrome/browser/resources/settings/date_time_page/date_time_page.html

 <link rel="import" href="chrome://resources/html/polymer.html">
-<link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-checkbox/paper-checkbox.html">
 <link rel="import" href="/controls/settings_checkbox.html">
 <link rel="import" href="/settings_shared_css.html">
 
 <dom-module id="settings-date-time-page">
   <template>
     <style include="settings-shared"></style>
-    <div class="settings-box first block">
-      <div disabled$="[[!pageVisibility.timeZoneSelector]]">
-        $i18n{timeZone}

[michaelpg, 2016/10/06 03:50:09]

didn't delete from settings_strings.grdp because it's going back in next CL.

-      </div>
+    <div class="settings-box first">
+      <!-- TODO(michaelpg): Time zone dropdown menu. -->

[dpapad, 2016/10/06 18:01:14]

Just FYI, when you get to this, let's use <select class="md-select">. There are
plenty examples in the codebase of native selects styled as MD now.

[michaelpg, 2016/10/06 18:22:49]

I assume this means it's also okay to use settings-dropdown-menu here (since it
wraps a <select class="md-select">)? I'd like to use its functionality here.

       <settings-checkbox pref="{{prefs.settings.clock.use_24hour_clock}}"
           label="$i18n{use24HourClock}">
       </settings-checkbox>
-      <div id="setAutomatically">$i18n{dateTimeSetAutomatically}</div>
     </div>
+    <paper-checkbox class="settings-box continuation"

[dpapad, 2016/10/06 18:01:14]

Is there a preference of hiding this checkbox with hidden VS wrapping it in a
<template is="dom-if" if="[[hideTimeZoneDetection_]]" ? Perhaps the latter is
slightly cheaper?

[michaelpg, 2016/10/06 18:22:50]

Yes, definitely: A <template is="dom-if"> introduces extra overhead. Not much,
but if the majority of cases will show the contents immediately, we shouldn't
use <template> unless it's reeeally big.

hideTimeZoneDetection_ is controlled by a --command-line-flag so it is
definitely not the common case, and I'm not worried about one unnecessary
paper-checkbox when people enable that flag.

+        id="timeZoneDetectionCheckbox"
+        hidden="[[hideTimeZoneDetection_]]"
+        on-change="onTimeZoneDetectionCheckboxChange_">
+      $i18n{timeZoneGeolocation}
+    </paper-checkbox>
   </template>
   <script src="date_time_page.js"></script>
 </dom-module>