DevTools: convert a few more icons to UI.Icon.

third_party/WebKit/Source/devtools/front_end/console/consoleView.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 349 matching lines @@
     flex: 1 1 auto;
     display: flex;
     flex-direction: column;
     align-items: stretch;
 }
 
 .console-message-stack-trace-wrapper > * {
     flex: none;
 }
 
-.console-message-stack-trace-toggle .console-message-text::before {
-    content: " ";
-    -webkit-user-select: none;
-    -webkit-mask-image: url(Images/toolbarButtonGlyphs.png);
-    -webkit-mask-size: 352px 168px;
-    color: transparent;
-    text-shadow: none;
-    padding-right: 8px;
-    height: 12px;
+.stack-trace-expand-icon {
     background-color: rgb(110, 110, 110);

[dgozman, 2016/12/14 19:18:25]

Can we make this background color default? That would be beautiful, since nobody
will have to need anything about the icon!

[lushnikov, 2016/12/14 22:02:54]

I'll keep this as-is since this would break dark theme

-    width: 12px;
-    flex: none;
-    -webkit-mask-position: -4px -96px;
 }
-
-@media (-webkit-min-device-pixel-ratio: 1.1) {
-.console-message-stack-trace-toggle .console-message-text::before {
-    -webkit-mask-image: url(Images/toolbarButtonGlyphs_2x.png);
-}
-} /* media */
-
-.console-message-stack-trace-toggle.expanded .console-message-text::before {
-    -webkit-mask-position: -20px -96px;
-}