[DevTools] Upon active timeline recording, label cursor should behave as a default cursor.

Source/devtools/front_end/timelinePanel.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 798 matching lines @@
 }
 
 .paint-profiler-image-view {
     overflow: hidden;
 }
 
 .paint-profiler-image-view img {
     border: solid 1px black;
     -webkit-transform-origin: 0px 0px;
 }
-
-label.dimmed {
-    opacity: 0.6;
-}