DevTools: Add dark theme hidden experiment

third_party/WebKit/Source/devtools/front_end/inspectorStyle.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 28 matching lines @@
     overflow: hidden;
     margin: 0;
     cursor: default;
     font-family: Lucida Grande, sans-serif;
     font-size: 12px;
     tab-size: 4;
     -webkit-user-select: none;
     color: #222;
 }
 
+body.dark-theme {
+    -webkit-filter: invert(100%);
+}
+
 .platform-linux {
     color: rgb(48, 57, 66);
     font-family: Ubuntu, Arial, sans-serif;
 }
 
 .platform-mac {
     color: rgb(48, 57, 66);
     font-family: 'Lucida Grande', sans-serif;
 }
 
@@ skipping 486 matching lines @@
     z-index: 20000;
 }
 
 .root-view {
     overflow: hidden;
     position: absolute !important;
     left: 0;
     top: 0;
     right: 0;
     bottom: 0;
+    background: white;

[pfeldman, 2015/11/21 06:07:05]

move this into

body.dark-theme .root-view

[paulirish, 2015/11/21 07:20:14]

done.

 }
 
 .viewport-control-gap-element {
     color: transparent;
 }
 
 .drawer-toolbar {
     margin-right: -6px;
 }