ChromeOS OOBE: fix focus indicator on Accessibility page.

chrome/browser/resources/chromeos/login/oobe_a11y_option.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-toggle-button/paper-toggle-button.html">
 
 <dom-module name="oobe-a11y-option">
   <template>
+    <style>
+      :root {
+          --oobe-toggle-button-size: {
+            box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.4);
+            height: 16px;
+            top: -2px;
+            width: 16px;
+          };
+          --oobe-toggle-bar-size: {
+            height: 12px;
+            left: 4px;
+            width: 24px;
+          };
+          --paper-toggle-button-checked-bar: var(--oobe-toggle-bar-size);
+          --paper-toggle-button-checked-button: {
+            @apply(--oobe-toggle-button-size);
+            transform: translate(14px, 0);
+          };
+          --paper-toggle-button-label-spacing: 0;
+          --paper-toggle-button-unchecked-bar: var(--oobe-toggle-bar-size);
+          --paper-toggle-button-unchecked-button:
+              var(--oobe-toggle-button-size);
+      }
+    </style>
     <link rel="stylesheet" href="oobe_a11y_option.css">
     <div id="elementBox" class="layout horizontal">
       <div class="flex layout vertical center-justified">
         <div id="titleContainer">
           <content select=".title"></content>
         </div>
         <div class="display-value" hidden="[[!checked]]">
           <content select=".checked-value"></content>
         </div>
         <div class="display-value" hidden="[[checked]]">
           <content select=".unchecked-value"></content>
         </div>
       </div>
       <paper-toggle-button checked="{{checked}}" aria-label$="[[ariaLabel]]">
       </paper-toggle-button>
     </div>
   </template>
 </dom-module>