Settings: Internet page cleanup

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">
       :host-context([dir=rtl]) button[is='paper-icon-button-light'] {
         transform: scaleX(-1);  /* Flip on the X axis (aka mirror). */
       }
@@ skipping 61 matching lines @@
           -webkit-padding-start: var(--settings-button-edge-spacing);
           font-weight: 500;
           text-align: start;
         };
         --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 299 matching lines @@
         transform: rotate(-135deg);
       }
 
       .column-header {
         color: var(--paper-grey-600);
         font-weight: 500;
       }
     </style>
   </template>
 </dom-module>