Settings: Fix disabled primary buttons

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">
       /* Use <h2> as the "sub-header" mentioned in the UX design docs. */
       h2 {
         align-items: center;
@@ skipping 75 matching lines @@
       }
 
       /* Adjust the margin between the separator and the first button. */
       .settings-box .separator + paper-button {
         -webkit-margin-start: calc(var(--settings-button-edge-spacing) * -1);
       }
 
       /* There are two settings button styles, .primary-button and normal
        * buttons. The primary is the action button (e.g. "edit", "delete")
        * while the normal (secondary-button) is often a "Cancel" button. */
-      .primary-button {
-        --paper-button: {
-          -webkit-padding-end: var(--settings-button-edge-spacing);
-          -webkit-padding-start: var(--settings-button-edge-spacing);
-          font-weight: 500;
-          text-align: start;
-        };
+      .primary-button:not([disabled]) {
         --paper-button-flat-keyboard-focus: {
           background: rgba(51, 103, 214, .12);  /* --google-blue-700 */
         };
         color: var(--google-blue-500);
       }
 
-      .primary-button[disabled] {
-        background: none;
-        color: var(--paper-grey-600);
-      }
-
       paper-toggle-button {
         @apply(--settings-actionable);
         height: var(--settings-row-min-height);
         width: 36px;
       }
 
       span ~ a {
         -webkit-margin-start: 4px;
       }
 
@@ skipping 294 matching lines @@
         transform: rotate(-135deg);
       }
 
       .column-header {
         color: var(--paper-grey-600);
         font-weight: 500;
       }
     </style>
   </template>
 </dom-module>