DevTools: fix zoomed color swatch size.

Source/devtools/front_end/inspectorStyle.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 1725 matching lines @@
 }
 
 .swatch {
     margin-left: 1px;
     margin-right: 2px;
     width: 10px;
     height: 10px;
     position: relative;
     top: 1px;
     display: inline-block;
+    line-height: 1px;
     background-image: url(Images/checker.png);
     -webkit-user-select: none;
 }
 
 .swatch-inner {
     width: 100%;
     height: 100%;
     display: inline-block;
     border: 1px solid rgba(128, 128, 128, 0.6);
 }
@@ skipping 1047 matching lines @@
 }
 
 .resources-divider-label {
     position: absolute;
     top: 4px;
     right: 3px;
     font-size: 80%;
     white-space: nowrap;
     pointer-events: none;
 }