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

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

Index: chrome/browser/resources/settings/controls/controlled_button.html
diff --git a/chrome/browser/resources/settings/controls/controlled_button.html b/chrome/browser/resources/settings/controls/controlled_button.html
index 7f4e69d4bded78e4317fee1dea523a7e3220b356..e1aee58740abc4537c2de8df64f16d1bc03a2596 100644
--- a/chrome/browser/resources/settings/controls/controlled_button.html
+++ b/chrome/browser/resources/settings/controls/controlled_button.html
@@ -39,9 +39,16 @@
       }
     </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_">