NetworkPanel: Make "sticky" behavior explicit.

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 536 matching lines @@
     text-shadow: rgba(255, 255, 255, 0.75) 0 1px 0;
     -webkit-appearance: none;
     border: 0;
     border-radius: 0;
     padding: 0 15px 0 5px;
     margin-right: -10px;
     position: relative;
     line-height: 20px;
 }
 
+.status-bar-item.checkbox {
+    margin: 2px 0 0 0;
+}
+
 .status-bar-item > .glyph {
     -webkit-mask-image: url(Images/statusbarButtonGlyphs.png);
     -webkit-mask-size: 320px 120px;
     opacity: 0.8;
 }
 
 .console-filter > .glyph {
     -webkit-mask-position: -32px -48px;
 }
 
@@ skipping 2249 matching lines @@
     display: inline-block;
     float: right;
     padding-right: 4px;
     padding-top: 4px;
     padding-left: 2px;
 }
 
 body.undocked .toolbar-close-button-item {
     display: none;
 }