MD Settings: change outlinks to actually use <a>

chrome/browser/resources/settings/settings_shared_css.html

 <link rel="import" href="chrome://resources/cr_elements/shared_style_css.html">
 <link rel="import" href="settings_vars_css.html">
 
 <!-- Common styles for Material Design settings. -->
 <dom-module id="settings-shared">
   <template>
     <style include="cr-shared-style">
       /* Included here so we don't have to include "iron-positioning" in every
        * stylesheet. See crbug.com/498405. */
       [hidden] {
@@ skipping 55 matching lines @@
       .tertiary-button {
         --paper-button-flat-keyboard-focus: {
           background: rgba(51, 103, 214, .12);  /* --google-blue-700 */
         };
       }
 
       a[href] {
         text-decoration: none;
       }
 
+      a[href][tabindex='-1'] {
+        color: var(--paper-grey-900);
+        outline: none;
+      }
+
       /* There are three main button styles, .primary-button, .secondary-button,
        * and .tertiary-button. The primary is the action button (e.g. "edit",
        * "delete") while the secondary is often a "Cancel" button. A tertiary
        * button may be used to get more information or similar, that we expect
        * most users will not need. */
       .primary-button {
         --paper-button: {
           font-weight: 500;
           text-align: start;
         };
@@ skipping 306 matching lines @@
         transform: rotate(-135deg);
       }
 
       .column-header {
         color: var(--paper-grey-600);
         font-weight: 500;
       }
     </style>
   </template>
 </dom-module>