MD Settings: Switch cr_network_icon to use svg icons

chrome/browser/resources/options/browser_options.css

 /* Copyright (c) 2012 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. */
 
 #change-home-page-section {
   -webkit-margin-start: 30px;
 }
 
 #home-page-url {
   display: inline-block;
@@ skipping 203 matching lines @@
 }
 
 .network-group-labels {
   -webkit-box-flex: 1;
   -webkit-box-orient: vertical;
   display: -webkit-box;
   padding-top: 3px;
 }
 
 .network-icon {
-  -webkit-margin-end: 8px;
+  -webkit-margin-end: 10px;
   background-position: left top;
   background-size: 25px;
   height: 25px;
   line-height: normal;
   white-space: normal;
   width: 25px;
 }
 
 .network-icon cr-network-icon {
   height: 100%;
@@ skipping 248 matching lines @@
 
 /* An input that has no function except to take up the same amount of space as
  * a checkbox. */
 .spacer-checkbox {
   visibility: hidden;
 }
 
 #android-apps-settings {
   -webkit-margin-start: 30px;
 }