Devtools: Add global animation timeline controls

Source/devtools/front_end/elements/elementsPanel.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 693 matching lines @@
     display: none;
 }
 
 .animationSectionBody.expanded {
     display: block;
 }
 
 .animationSectionBody .section {
     border-bottom: 1px solid rgb(191, 191, 191);
 }
+
+.animationsHeader {
+    padding-top: 25px;
+}
+
+.global-animations-toolbar {
+    position: absolute;
+    top: 0;
+    width: 100%;
+    background-color: #eee;
+    border-bottom: 1px solid rgb(163, 163, 163);
+}
+
+.playback-rate-button.toggled-on > .status-bar-button-text {
+    color: rgb(66, 129, 235);
+}