Add lots of 2x assets

chrome/browser/resources/plugins.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. */
 
 body {
   margin: 10px;
   min-width: 47em;
 }
 
 a {
   color: blue;
   font-size: 103%;
 }
 
 div#header {
   -webkit-padding-start: 0;
   box-sizing: border-box;
   margin-bottom: 1.05em;
   /* 67px is the height of the header's background image. */
   min-height: 67px;
   overflow: hidden;
   padding-bottom: 20px;
   padding-top: 20px;
   position: relative;
 }
 
 #header h1 {
-  background: url('../../app/theme/extensions_section.png') 0 20px no-repeat;
+  background: url('../../app/theme/default_100_percent/extensions_section.png') 0 20px no-repeat;
   display: inline;
   margin: 0;
   padding-bottom: 20px;
   padding-left: 75px;
   padding-top: 40px;
 }
 
 html[dir=rtl] #header h1 {
-  background: url('../../app/theme/extensions_section.png') right no-repeat;
+  background: url('../../app/theme/default_100_percent/extensions_section.png') right no-repeat;
   padding-left: 0;
   padding-right: 95px;
 }
 
 h1 {
   font-size: 156%;
   font-weight: bold;
   margin: 0;
   padding: 0;
 }
@@ skipping 190 matching lines @@
   margin-top: 0.2em;
 }
 
 .always-allow {
   -webkit-margin-start: 30px;
 }
 
 button {
   font-size: 104%;
 }