MD Settings: Fix date and time layout

chrome/browser/resources/settings/a11y_page/manage_a11y_page.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="../controls/settings_toggle_button.html">
 <link rel="import" href="../i18n_setup.html">
 <link rel="import" href="../route.html">
 <link rel="import" href="../settings_shared_css.html">
 <link rel="import" href="../settings_vars_css.html">
 
 <dom-module id="settings-manage-a11y-page">
   <template>
     <style include="settings-shared">
       h2 {
         -webkit-padding-start: var(--settings-box-row-padding);
       }
 
       .list-item settings-dropdown-menu {
         -webkit-margin-start: 16px;
       }
 
       h2 ~ .settings-box {
         -webkit-margin-end: var(--settings-box-row-padding);
-        -webkit-margin-start: calc(
-            var(--settings-box-row-padding) + var(--settings-indent-width));
+        -webkit-margin-start: var(--settings-box-row-indent);
         -webkit-padding-end: 0;
         -webkit-padding-start: 0;
       }
     </style>
     <div class="settings-box row first">
       <span>
         $i18n{a11yExplanation}
         <a href="$i18nRaw{a11yLearnMoreUrl}" target="_blank">
           $i18n{learnMore}
         </a>
@@ skipping 146 matching lines @@
           $i18n{a11yWebStore}
         </div>
       </div>
       <button class="icon-external" is="paper-icon-button-light"
           aria-label="$i18n{additionalFeaturesTitle}"
           aria-describedby="moreFeaturesSecondary"></button>
     </div>
   </template>
   <script src="manage_a11y_page.js"></script>
 </dom-module>