DevTools: NetworkPanel: remove noop CSS.

Source/devtools/front_end/webSocketFrameView.css

 /*
  * Copyright (c) 2014 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 .websocket-frame-view {
     -webkit-user-select: text;
 }
 
@@ skipping 10 matching lines @@
 .websocket-frame-view .data-grid .data {
     background-image: none;
 }
 
 .websocket-frame-view-td {
     padding-top: 3px;
     padding-bottom: 3px;
     border-bottom: 1px solid #aaa;
 }
 
-.websocket-frame-view .top-filler-td,
-.websocket-frame-view .bottom-filler-td {
-    border-bottom: none;
-}
-
 .websocket-frame-view-row-outcoming {
     background-color: rgb(226, 247, 218);
 }
 
 .websocket-frame-view-row-opcode {
     background-color: rgb(255, 255, 232);
     color: rgb(170, 111, 71);
 }
 
 .websocket-frame-view-row-error {
     background-color: rgb(255, 237, 237);
     color: rgb(182, 0, 0);
 }