MD Settings: Allow controlled-button to be used with icons.

chrome/browser/resources/settings/controls/controlled_button.html

 <link rel="import" href="chrome://resources/html/assert.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_indicator_behavior.html">
 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_pref_behavior.html">
 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_pref_indicator.html">
 <link rel="import" href="pref_control_behavior.html">
 <link rel="import" href="../i18n_setup.html">
 <link rel="import" href="../settings_shared_css.html">
 
 <dom-module id="controlled-button">
   <template>
     <style include="settings-shared">
       :host {
         align-items: center;
         display: flex;
         --justify-margin: 18px;
       }
 
-      :host([controlled_]) {
+      :host([controlled]) {
         /* Disable pointer events for this whole element, as outer on-tap gets
          * triggered when clicking/tapping anywhere in :host. */
         pointer-events: none;
       }
 
       cr-policy-pref-indicator {
         /* Enable pointer events for the indicator so :hover works. Disable
          * clicks/taps via onIndicatorTap_ so outer on-tap doesn't trigger. */
         pointer-events: all;
       }
 
       :host(:not([end-justified])) cr-policy-pref-indicator {
         -webkit-margin-start: var(--justify-margin);
       }
 
       :host([end-justified]) cr-policy-pref-indicator {
         -webkit-margin-end: var(--justify-margin);
         order: -1;
       }
     </style>
 
-    <paper-button disabled="[[controlled_]]">
-      <content></content>
-    </paper-button>
+    <template is="dom-if" if="[[iconClass]]">
+      <button is="paper-icon-button-light" disabled="[[controlled]]"
+          actionable class$="{{iconClass}}"></button>
+    </template>
+
+    <template is="dom-if" if="[[!iconClass]]">
+      <paper-button disabled="[[controlled]]">
+        <content></content>
+      </paper-button>
+    </template>
 
     <template is="dom-if" if="[[showIndicator_(pref)]]" restamp>
       <cr-policy-pref-indicator pref="[[pref]]" on-tap="onIndicatorTap_">
       </cr-policy-pref-indicator>
     </template>
 
   </template>
   <script src="controlled_button.js"></script>
 </dom-module>