MD-Settings: Adds an a11y label to most toggle buttons.

chrome/browser/resources/settings/internet_page/network_siminfo.html

 <link rel="import" href="chrome://resources/cr_elements/cr_dialog/cr_dialog.html">
 <link rel="import" href="chrome://resources/cr_elements/network/cr_onc_types.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-a11y-keys/iron-a11y-keys.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.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-input/paper-input.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-toggle-button/paper-toggle-button.html">
 <link rel="import" href="../icons.html">
 <link rel="import" href="internet_shared_css.html">
@@ skipping 58 matching lines @@
       <div class="secondary-action">
         <paper-button on-tap="onUnlockPinTap_">
           $i18n{networkSimUnlock}
         </paper-button>
       </div>
     </div>
 
     <!-- SIM unlocked -->
     <div class="settings-box two-line"
         hidden$="[[!showSimUnlocked_(networkProperties)]]">
-      <div class="start">$i18n{networkSimLockEnable}</div>
+      <div id="simLockToggleLabel" class="start">
+        $i18n{networkSimLockEnable}
+      </div>
       <paper-button on-tap="onChangePinTap_"
           hidden$="[[!networkProperties.Cellular.SIMLockStatus.LockEnabled]]">
         $i18n{networkSimChangePin}
       </paper-button>
       <paper-toggle-button on-change="onSimLockEnabledChange_"
-          checked="[[networkProperties.Cellular.SIMLockStatus.LockEnabled]]">
+          checked="[[networkProperties.Cellular.SIMLockStatus.LockEnabled]]"
+          aria-labelledby="simLockToggleLabel">
       </paper-toggle-button>
     </div>
 
     <!-- Enter PIN dialog -->
     <dialog is="cr-dialog" id="enterPinDialog">
       <div class="title">$i18n{networkSimEnterPinTitle}</div>
       <div class="body">
         <paper-input id="enterPin" class="pin" no-label-float
             label="$i18n{networkSimEnterPin}">
           <iron-a11y-keys keys="enter" on-keys-pressed="sendEnterPin_">
@@ skipping 83 matching lines @@
       </div>
       <div class="button-container">
         <paper-button on-tap="sendUnlockPuk_">
           $i18n{networkSimUnlock}
         </paper-button>
       </div>
     </dialog>
   </template>
   <script src="network_siminfo.js"></script>
 </dom-module>