Settings People Revamp: Add tests for ChromeOS Change Picture.

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

 <link rel="import" href="chrome://resources/html/i18n_behavior.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://md-settings/people_page/change_picture_private_api.html">
 
 <dom-module id="settings-change-picture">
   <link rel="import" type="css"
       href="chrome://md-settings/settings_shared.css">
   <link rel="import" type="css" href="change_picture.css">
   <template>
     <div class="settings-box">
       <div class="split">
         <div id="availableIcons">
-          <paper-button toggles
+          <paper-button id="profile-image" toggles
               active="{{isActiveImage_(profileImageUrl_, selectedImageUrl_)}}"
               on-tap="onProfileImageTap_">
             <img class="user-image" src="[[profileImageUrl_]]"
                 alt="[[i18n('profilePhotoLoading')]]">
           </paper-button>
           <template is="dom-if" if="[[oldImageUrl_]]">
-            <paper-button toggles
+            <paper-button id="old-image" toggles
                 active="{{isActiveImage_(oldImageUrl_, selectedImageUrl_)}}"
                 on-tap="onOldImageTap_">
               <img class="user-image" src="[[oldImageUrl_]]">
             </paper-button>
           </template>
           <template is="dom-repeat" items="[[defaultImages_]]">
-            <paper-button toggles
+            <paper-button class="default-image" toggles
                 active="{{isActiveImage_(item.url, selectedImageUrl_)}}"
                 on-tap="onDefaultImageTap_" data-image-url$="[[item.url]]">
               <img class="user-image" src="[[item.url]]" alt="[[item.title]]">
             </paper-button>
           </template>
         </div>
       </div>
     </div>
   </template>
   <script src="change_picture.js"></script>
 </dom-module>