DevTools: fix timeline banners to scroll on overflow

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 34 matching lines @@
     justify-content: center;
     align-items: center;
     text-align: center;
     padding: 20px;
     position: absolute;
     top: 0;
     right: 0;
     bottom: 0;
     left: 0;
     font-size: 13px;
+    overflow: auto;
 }
 
 .panel.timeline .banner a,
 .panel.layers .banner a {
     color: inherit;
 }
 
 #timeline-overview-panel .timeline-graph-bar {
     pointer-events: none;
 }
@@ skipping 665 matching lines @@
     border-bottom: 1px solid #ddd;
     background-color: #f3f3f3
 }
 
 .timeline-stack-view-header {
     height: 26px;
     background-color: white;
     padding: 6px 10px;
     color: #5a5a5a;
 }