DevTools: CSS cleanup.

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 337 matching lines @@
     display: inline-block;
     height: 11px;
     margin-right: 2px;
     margin-left: 6px;
     position: relative;
     top: 2px;
     width: 10px;
     border: solid 1px;
 }
 
-.popover .timeline-aggregated-category.timeline-loading {
-    margin-left: 0;
-}
-
 .popover ul {
     margin: 0;
     padding: 0;
     list-style-type: none;
 }
 
 .timeline-garbage-collect-status-bar-item .glyph {
     -webkit-mask-position: -128px -24px;
 }
 
@@ skipping 379 matching lines @@
 }
 
 .paint-profiler-image-view {
     overflow: hidden;
 }
 
 .paint-profiler-image-view img {
     border: solid 1px black;
     -webkit-transform-origin: 0px 0px;
 }