Add a very basic PIN UI implementation that is shared between lock and settings.

chrome/browser/resources/settings/people_page/people_page.html

Index: chrome/browser/resources/settings/people_page/people_page.html
diff --git a/chrome/browser/resources/settings/people_page/people_page.html b/chrome/browser/resources/settings/people_page/people_page.html
index 7565ad770469f089982a1dc0f421a0aa39c476ad..37b4b3f57c496e2f695d623a2c47b57dd59f9884 100644
--- a/chrome/browser/resources/settings/people_page/people_page.html
+++ b/chrome/browser/resources/settings/people_page/people_page.html
@@ -15,6 +15,7 @@
 
 <if expr="chromeos">
 <link rel="import" href="chrome://md-settings/people_page/change_picture.html">
+<link rel="import" href="chrome://md-settings/people_page/pin.html">
 <link rel="import" href="chrome://md-settings/people_page/easy_unlock_browser_proxy.html">
 <link rel="import" href="chrome://md-settings/people_page/easy_unlock_turn_off_dialog.html">
 <link rel="import" href="chrome://md-settings/people_page/users_page.html">
@@ -101,6 +102,16 @@
         </template>
 
 <if expr="chromeos">
+        <!-- TODO(jdufault): Confirm if this goes above or below easy unlock
+             settings. -->
+        <template is="dom-if" if=[[pinUnlockAllowed_]]>

[tommycli, 2016/05/04 19:29:03]

Hmm... it appears that this just embeds the pin-keyboard within the People
section? Do you have a link to the mocks for PIN unlock within Settings?

If this isn't ready perhaps we can split off the Settings portion of this review
into a separate CL

[jdufault, 2016/05/06 00:05:46]

UI review mocks are at go/rwftg.

My primary intent with this CL is to setup the code-sharing structure, since
there are a fair number of changes/new-files needed to make that happen.

If you prefer, I can pull the settings changes out of this CL and upload them
later once they are more fleshed out. If that ends up happening, I'd like to
first confirm that the overall code-layout/sharing structure looks good.

[tommycli, 2016/05/06 18:15:44]

Okay cool, thanks for the mocks. That helps me a lot. Assuming the code sharing
works, since this is hidden (given pinUnlockAllowed_ is false), I'm fine with
it.

[jdufault, 2016/05/06 23:44:17]

Thanks - the code sharing does indeed work.

+          <div class="settings-box">
+            <!-- TODO(jdufault): i18n -->
+            <p>Quick Unlock PIN</p>
+            <pin-keyboard></pin-keyboard>
+          </div>
+        </template>
+
         <div class="settings-box">
           <settings-checkbox pref="{{prefs.settings.enable_screen_lock}}"
               i18n-values="label:enableScreenlock">