[DevTools] Prepare to move Popover to shadow DOM.

third_party/WebKit/Source/devtools/front_end/timeline/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 266 matching lines @@
 }
 
 #counter-values-bar {
     flex: 0 0 20px;
     border-top: solid 1px lightgray;
     width: 100%;
     overflow: hidden;
     line-height: 18px;
 }
 
-.image-preview-container {
-    background: transparent;
-    text-align: left;
-    border-spacing: 0;
-    margin: 4px;
-}
-
-.image-preview-container img {
-    max-width: 100px;
-    max-height: 100px;
-    background-image: url(Images/checker.png);
-    -webkit-user-select: text;
-    -webkit-user-drag: auto;
-}
-
-.image-container {
-    padding: 0;
-}
-
 .timeline-filters-header {
     overflow: hidden;
     flex: none;
 }
 
 .timeline-details {
     vertical-align: top;
 }
 
 .timeline-details-title {
@@ skipping 376 matching lines @@
 
 .timeline-landing-warning-close {
     float: right;
     margin-top: -10px;
     margin-right: -13px;
 }
 
 .timeline-landing-warning span[is=ui-icon] {
     margin: -8px;
 }