[DevTools] Fix overlapping while editing blocked url.

Source/devtools/front_end/network/blockedURLsPane.css

 /*
  * Copyright (c) 2015 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.
  */
 
 .toolbar {
     border-bottom: 1px solid #dadada;
 }
 
@@ skipping 24 matching lines @@
     flex: 30px 0 0;
     font-size: smaller !important;
     padding-right: 5px;
 }
 
 .blocked-url-text {
     white-space: nowrap;
     text-overflow: ellipsis;
     overflow: hidden;
     flex: auto;
+    margin-right: 5px;
 }
 
 .blocked-url .remove-button {
     width: 13px;
     height: 13px;
     background-image: url(Images/toolbarButtonGlyphs.png);
     background-size: 352px 168px;
     background-position: -175px -96px;
     visibility: hidden;
     flex: none;
     opacity: 0.7;
     cursor: default;
 }
 
 @media (-webkit-min-device-pixel-ratio: 1.5) {
 .blocked-url .remove-button {
     background-image: url(Images/toolbarButtonGlyphs_2x.png);
 }
 } /* media */
 
 .blocked-url:hover .remove-button {
     visibility: visible;
 }
 
 .blocked-url .remove-button:hover {
     opacity: 1.0;
 }