DevTools: fix toolbar <select> background in Dark theme

third_party/WebKit/Source/devtools/front_end/ui/toolbar.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.
  */
 
 :host {
     flex: none;
     padding: 0 2px;
 }
@@ skipping 164 matching lines @@
 } /* media */
 
 select.toolbar-item {
     min-width: 48px;
     -webkit-appearance: none;
     border: 0;
     border-radius: 0;
     padding: 0 15px 0 5px;
     margin-right: -10px;
     position: relative;
+    background-color: white;
 }
 
 /* Input */
 
 input.toolbar-item {
     width: 200px;
     height: 20px;
     padding: 3px;
     margin: 1px 3px;
     background-color: white;
@@ skipping 293 matching lines @@
 .toolbar-state-active .filter-toolbar-item.toolbar-glyph,
 .toolbar-state-active .block-toolbar-item.toolbar-glyph {
     background-color: rgb(216, 0, 0) !important;
 }
 
 :host-context(.-theme-with-dark-background) .toolbar-state-active .filter-toolbar-item.toolbar-glyph,
 :host-context(.-theme-with-dark-background) .toolbar-state-active .block-toolbar-item.toolbar-glyph,
 :host-context(.-theme-with-dark-background) .toolbar-state-on .record-toolbar-item.toolbar-glyph {
     background-color: hsl(0, 100%, 65%) !important;
 }