MD Settings: Display > Overscan: Update text and fix focus

chrome/browser/resources/settings/device_page/display_overscan_dialog.html

 <link rel="import" href="chrome://resources/cr_elements/cr_dialog/cr_dialog.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.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/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="/icons.html">
 <link rel="import" href="/settings_shared_css.html">
 
 <dom-module id="settings-display-overscan-dialog">
   <template>
     <style include="settings-shared">
-     .label {
-       margin: 10px 0;
+     .subtitle {
+       margin-top: 10px;
      }
+
+     .instructions {
+       color: var(--paper-grey-600);
+       margin-top: 4px;
+     }
+
      .details {
        margin: 40px;
      }
+
      iron-icon {
        --iron-icon-fill-color: white;
        background: black;
-       margin: 2px;
+       margin: 5px;
      }
+
      #move > div {
        color: grey;
        font-size: 150%;
      }
+
      #move > div.shift {
        background: black;
        color: white;
        font-size: 100%;
        margin: 0 8px;
        padding: 4px 8px 0;
      }
     </style>
     <dialog is="cr-dialog" id="dialog" on-close="close">
       <div class="title">$i18n{displayOverscanPageTitle}</div>
       <div class="body">
-        <div class="label self-start" >$i18n{displayOverscanInstructions}</div>
+        <div class="subtitle" >$i18n{displayOverscanSubtitle}</div>
+        <div class="instructions" >$i18n{displayOverscanInstructions}</div>
         <div class="details layout horizontal around-justified self-stretch">
           <div class="layout vertical center">
             <div class="layout horizontal">
               <iron-icon icon="cr:expand-less"></iron-icon>
             </div>
             <div class="layout horizontal">
               <iron-icon icon="settings:chevron-left"></iron-icon>
               <iron-icon icon="cr:expand-more"></iron-icon>
               <iron-icon icon="cr:chevron-right"></iron-icon>
             </div>
             <div class="label" >$i18n{displayOverscanResize}</div>
           </div>
           <div class="layout vertical center">
             <div class="layout vertical center-justified flex">
               <div id="move" class="layout horizontal">
                 <!-- TODO(stevenjb): Localize 'shift' for other keyboards -->
                 <!-- crbug.com/614827 -->
                 <div>( + </div><div class="shift">shift</div><div>)</div>
               </div>
             </div>
             <div class="label">$i18n{displayOverscanPosition}</div>
           </div>
         </div>
       </div>
       <div class="button-container">
-        <paper-button class="secondary-button" on-tap="onResetTap_">
+        <paper-button id="reset" class="secondary-button" on-tap="onResetTap_">
           $i18n{displayOverscanReset}
         </paper-button>
-        <paper-button class="primary-button"  on-tap="onSaveTap_">
-          $i18n{displayOverscanSave}
+        <paper-button class="primary-button" on-tap="onSaveTap_">
+          $i18n{ok}
         </paper-button>
       </div>
     </dialog>
   </template>
   <script src="display_overscan_dialog.js"></script>
 </dom-module>