Add lots of 2x assets

chrome/browser/resources/crashes.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: 20px;
 }
 
 h1 {
   -webkit-padding-start: 75px;
   /* TODO(stuartmorgan): Get real art for this image */
-  background-image: url('../../app/theme/sadtab.png');
+  background-image: url('../../app/theme/default_100_percent/sadtab.png');

[flackr, 2012/06/21 21:19:21]

For this and other assets where a 2x file exists please change this to the
following so that we can use the 2x asset in WebUI:
background-image: -webkit-image-set(
    url('../../app/theme/default_100_percent/sadtab.png') 1x,
    url('../../app/theme/default_200_percent/sadtab.png') 2x);

   background-position: left;
   background-repeat: no-repeat;
   font-size: 156%;
   font-weight: bold;
   margin: 0;
   padding-bottom: 20px;
   padding-top: 20px;
 }
 
 html[dir=rtl] h1 {
@@ skipping 21 matching lines @@
 }
 
 #crashList > div:not(:last-child) {
   border-bottom: 1px solid #bbb;
 }
 
 #disabledMode h2 {
   color: rgb(141, 51, 42);
   font-size: 125%;
 }