[WebUI] use one-way Polymer binding on dom-if, dom-repeat, and iron-list

chrome/browser/resources/chromeos/emulator/battery_settings.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-collapse/iron-collapse.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/iron-flex-layout-classes.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/neon-animation/neon-animatable-behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-checkbox/paper-checkbox.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-dropdown-menu/paper-dropdown-menu.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-input/paper-input.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-item/paper-item.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-listbox/paper-listbox.html">
@@ skipping 20 matching lines @@
           <template is="dom-repeat" items="[[batteryStateOptions]]">
             <paper-radio-button name="[[item]]">[[item]]</paper-radio-button>
           </template>
         </paper-radio-group>
       </label>
       <iron-collapse opened="[[isBatteryPresent(batteryState)]]">
         <div class="layout vertical">
           <paper-input label="Battery percentage" value="[[batteryPercent]]"
               on-change="onBatteryPercentChange" type="number">
           </paper-input>
-  
+
           <paper-input label="Seconds until empty" value="[[timeUntilEmpty]]"
               on-change="onTimeUntilEmptyChange" type="number">
           </paper-input>
 
           <paper-input label="Seconds until full" value="[[timeUntilFull]]"
               on-change="onTimeUntilFullChange" type="number">
           </paper-input>
         </div>
       </iron-collapse>
 
       <table class="devices-table">
         <tbody>
           <tr class="table-section-header">
             <td>Power sources</td>
             <td class="centered-cell-label">Connected</td>
             <td class="centered-cell-label">Role</td>
             <td class="centered-cell-label">Amps</td>
           </tr>
-          <template is="dom-repeat" items="{{powerSourceOptions}}">
+          <template is="dom-repeat" items="[[powerSourceOptions]]">
             <tr>
               <td class="alias-cell">[[item.name]]</td>
               <td class="control-cell">
                 <paper-checkbox checked="{{item.connected}}"></paper-checkbox>
               </td>
               <td class="control-cell">
                 <paper-button on-tap="onSetAsSourceTap"
                     hidden$="[[!isDualRole(item)]]"
                     raised="[[!isSelectedSource(item, selectedPowerSourceId)]]"
                     disabled="[[!canBecomeSource(
@@ skipping 12 matching lines @@
                   </paper-listbox>
                 </paper-dropdown-menu>
               </td>
           </template>
         </tbody>
       </table>
     </div>
   </template>
   <script src="battery_settings.js"></script>
 </dom-module>