ChromeOS OOBE: display icons specific to screen DPI.

chrome/browser/resources/chromeos/login/oobe_dialog_parameters.css

 /* Copyright 2016 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. */
 
-iron-icon.oobe-icon {
+hd-iron-icon.oobe-icon {
   --iron-icon-height: 32px;
   --iron-icon-width: 32px;
-  color: var(--google-blue-500);
+  --iron-icon-fill-color: var(--google-blue-500);
 }
 
 oobe-dialog .header {
   color: rgba(0, 0, 0, 0.87);
   font-family: Roboto, sans-serif;
 }
 
 oobe-dialog h1.title {
   color: rgba(0, 0, 0, 0.87);
   font-size: 28px;
   font-weight: normal;
   margin: 36px 0 0 0; /* = 64 - font height*/
 }
 
 oobe-dialog .subtitle {
   color: rgba(0, 0, 0, 0.87);
   font-size: 13px;
   margin: 23px 0 0 0; /* = 40 - 4 (adjustment) - line-height */
 }
 
 oobe-dialog .bottom-buttons {
   width: 100%
 }