MD Settings: Manage search engines 3/3, hooking up UI.

chrome/browser/resources/settings/settings_dialog.css

 /* Copyright 2015 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file. */
 
 /**
  * @fileoverview
  * Common dialog styles for Material Design settings.
  */
 
 paper-dialog {
@@ skipping 27 matching lines @@
 }
 
 paper-dialog .title,
 paper-dialog .body {
   -webkit-padding-end: 24px;
   -webkit-padding-start: 24px;
 }
 
 paper-dialog .action-button {
   -webkit-margin-start: 10px;
-  background-color: rgb(66, 133, 244);
-  color: white;
   font-weight: 500;
 }
 
+paper-dialog .action-button:not([disabled]) {
+  background-color: rgb(66, 133, 244);
+  color: white;
+}
+
 paper-dialog .cancel-button {
   color: rgb(109, 109, 109);
   font-weight: 500;
 }
 
 paper-dialog .explanation {
   margin-bottom: 35px;
 }
 
 paper-dialog .button-container {
   display: flex;
   justify-content: flex-end;
 }
 
 paper-dialog paper-button {
   margin: 0;
   min-width: auto;
 }
 
 paper-dialog paper-button[toggles][active] {
   background-color: LightGray;
 }