DevTools: NetworkPanel: remove noop CSS.

Source/devtools/front_end/networkLogView.css

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 53 matching lines @@
     vertical-align: middle;
 }
 
 .network-log-grid.data-grid.small td {
     height: 21px;
 }
 
 .network-log-grid.data-grid th {
     border-bottom: 1px solid rgb(205, 205, 205);
     border-left: 1px solid rgb(205, 205, 205);
-}
-
-.network-log-grid.data-grid th,
-.network-log-grid.data-grid th.sort-descending,
-.network-log-grid.data-grid th.sort-ascending {
     background: white;
 }
 
 .network-log-grid.data-grid .header-container {
     height: 31px;
 }
 
 .network-log-grid.data-grid .data-container {
     top: 31px;
 }
@@ skipping 480 matching lines @@
 
 #network-container {
     overflow-y: auto;
     overflow-x: hidden;
 }
 
 /* Brief mode peculiarities. */
 #network-container.brief-mode .network-timeline-grid {
     display: none;
 }
-
-#network-container.brief-mode td,
-#network-container.brief-mode th {
-    border-left: none;
-}
-
-#network-container.brief-mode .network-log-grid.data-grid .data-grid-resizer {
-    display: none;
-}
-
-#network-container.brief-mode .network-timeline-grid {
-    display: none;
-}
-
-#network-container:not(.brief-mode) .data-grid tr.selected {
-    background-color: transparent;
-    color: #222;
-}
-
-#network-container.brief-mode .data-grid .data-container {
-    padding-right: 0;
-}