Add cr-settings-radio-group wrapper

chrome/browser/resources/settings/appearance_page/appearance_page.html

 <link rel="import" href="chrome://resources/polymer/v1_0/polymer/polymer.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-radio-button/paper-radio-button.html">
 <link rel="import" href="chrome://md-settings/checkbox/checkbox.html">
-<link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
+<link rel="import" href="chrome://md-settings/radio_group/radio_group.html">
 
 <dom-module id="cr-settings-appearance-page">
   <link rel="import" type="css"
       href="chrome://md-settings/settings_page/settings_page.css">
   <link rel="import" type="css"
       href="chrome://md-settings/appearance_page/appearance_page.css">
   <link rel="import" type="css" href="chrome://resources/css/widgets.css">
   <link rel="import" href="chrome://resources/html/action_link.html">
   <template>
     <div id="action-container">
       <paper-button i18n-content="setWallpaper"></paper-button>
       <paper-button id="get-themes" i18n-content="getThemes"
           on-tap="openThemesGallery_">
       </paper-button>
       <paper-button id="resetTheme" i18n-content="resetToDefaultTheme" disabled
           on-tap="resetTheme_">
       </paper-button>
     </div>
     <hr>
     <cr-settings-checkbox pref="{{prefs.browser.show_home_button}}"
         i18n-values="label:showHomeButton">
     </cr-settings-checkbox>
-    <div id="change-home-page-section"
-        hidden$="[[!prefs.browser.show_home_button.value]]">
-      <div id="change-home-page-section-container">
-        <span id="home-page-ntp" i18n-content="homePageNtp"></span>
-        <span id="home-page-url"></span>
-        <a is="action-link" id="change-home-page"
-            i18n-content="changeHomePage">
-        </a>
-      </div>
+    <div class="radio-container">
+      <cr-settings-radio-group
+           hidden="[[!prefs.browser.show_home_button.value]]"

[Dan Beam, 2015/09/16 22:29:37]

lgtm assuming this (and possibly other things) get dom-if'd out when paper-*
elements are involved

[stevenjb, 2015/09/17 00:42:00]

I started a doc to discuss this sort of thing, but after reading more about
dom-if it seems clear that dom-if is a win, thanks for pointing that out.

+           pref="{{prefs.homepage_is_newtabpage}}">
+        <paper-radio-button name="true" i18n-content="homePageNtp">
+        </paper-radio-button>
+        <paper-radio-button name="false" i18n-content="openThisPage">
+        </paper-radio-button>
+      </cr-settings-radio-group>
     </div>
     <cr-settings-checkbox pref="{{prefs.bookmark_bar.show_on_all_tabs}}"
         i18n-values="label:showBookmarksBar">
     </cr-settings-checkbox>
   </template>
   <script src="appearance_page.js"></script>
 </dom-module>