DevTools: zoom frames upon double click, iterate over frames using arrows.

Source/devtools/front_end/network/networkPanel.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 238 matching lines @@
 
 .request-view.json {
     padding: 5px;
 }
 
 .request-view.html iframe {
     width: 100%;
     height: 100%;
     position: absolute;
 }
+
+.network-filmstrip-preview {
+    margin: 12px;
+}
+
+.network-filmstrip-preview > img {
+    border: 1px solid #ddd;
+}
+
+.network-filmstrip-preview-footer {
+    display: flex;
+    align-items: center;
+    margin-top: 10px;
+}
+
+.network-filmstrip-preview-label {
+    margin: 8px 2px;
+}