DevTools: Add timestamp support in the console

Source/devtools/front_end/inspector.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 839 matching lines @@
 }
 
 .console-adjacent-user-command-result {
     border-bottom: none;
 }
 
 .console-adjacent-user-command-result + .console-user-command-result.console-log-level::before {
     background-image: none;
 }
 
+.console-timestamp {
+    color: gray;
+    margin-right: 10px;
+    -webkit-user-select: none;
+}
+
 .console-message::before,
 .console-user-command::before,
 #console-prompt::before,
 .console-group-title::before {
     position: absolute;
     display: block;
     content: "";
     left: -17px;
     top: 0.8em;
     width: 10px;
@@ skipping 1964 matching lines @@
 }
 
 .root-view > .split-view > .split-view-sidebar {
     position: relative;
 }
 
 select.drop-down-menu {
     border: none;
     -webkit-appearance: none;
 }