deprecate webui.css

chrome/browser/resources/shared/css/button.css

 /* Copyright (c) 2011 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.
  */
 
 button:not(.custom-appearance),
 input[type='button']:not(.custom-appearance),
 input[type='submit']:not(.custom-appearance) {
   -webkit-border-radius: 2px;
   -webkit-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
@@ skipping 45 matching lines @@
 html:not([os='mac']) input[type='submit']:not(.custom-appearance):focus,
 html:not([os='mac']) select:not(.custom-appearance):focus {
   outline-color: rgba(0, 128, 256, 0.5);
 }
 
 html[os='mac'] button:not(.custom-appearance):focus,
 html[os='mac'] input[type='submit']:not(.custom-appearance):focus {
   outline-offset: -2px;
 }
 
-.link-button {
+/* TODO(jhawkins): Refactor button styling and remove !important here. This is
+ * currently necessary because individual page button element selectors have
+ * higher specificity.
+ */
+.link-button,
+.link-button:focus,
+.link-button:hover {
+  -webkit-box-shadow: none !important;
+  background: transparent none !important;
+  border: none !important;
+  color: rgb(63, 110, 194);
+  cursor: pointer;
   margin: 0;
-}
-
-.link-button,
-.link-button:hover,
-.link-button:focus {
-  color: rgb(63, 110, 194);
+  text-decoration: underline;
 }
 
 .link-button:active {
   color: rgb(37, 64, 113);
 }