Implement select listbox using shadow DOM

Source/core/css/themeMac.css

 /* Copyright 2014 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.
  */
 
 select, input[type="color"][list] {
     background-color: #f8f8f8;
     border: 1px solid #a6a6a6;
 }
 
 select[size],
 select[multiple],
 select[size][multiple] {
-    background: white;
-    border: 1px inset gray;
+    background-color: white;
+    border: 1px solid #999999;
+}
+
+select[size="0"],
+select[size="1"] {
+    background-color: #f8f8f8;
+    border: 1px solid #a6a6a6;
 }
 
 input::-webkit-inner-spin-button {
     align-self: center;
 }