DevTools: update buttons to new style

third_party/WebKit/Source/devtools/front_end/settings/frameworkBlackboxSettingsTab.css

 /*
  * Copyright 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.
  */
 
 :host {
     overflow:hidden;
 }
 
 .header {
     padding: 0 0 6px;
     border-bottom: 1px solid #EEEEEE;
     font-size: 18px;
     font-weight: normal;
     flex: none;
 }
 
 .blackbox-content-scripts {
     margin-top: 10px;
     flex: none;
 }
 
 .add-button {
-    margin: 10px 0;
+    margin: 10px 2px;
     align-self: flex-start;
     flex: none;
 }
 
 .blackbox-list {
     margin-top: 10px;
     max-width: 500px;
     flex: 0 1 auto;
     min-height: 30px;
 }
@@ skipping 58 matching lines @@
     flex-direction: row;
     margin: 6px 5px;
     align-items: center;
 }
 
 .blackbox-edit-row input,
 .blackbox-edit-row select {
     width: 100%;
     text-align: inherit;
 }