[Devtools] Fixed dark theme scrollbars consistency in settings

third_party/WebKit/Source/devtools/front_end/ui/inspectorCommon.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.
  */
 
 * {
     /* This is required for correct sizing of flex items because we rely
      * on an old version of the flexbox spec.
      * Longer-term we should remove this, see crbug.com/473625 */
@@ skipping 265 matching lines @@
 :host-context(:not(.platform-mac).-theme-with-dark-background) ::-webkit-scrollbar {
     width: 14px;
 }
 
 :not(.platform-mac).-theme-with-dark-background ::-webkit-scrollbar-track,
 :host-context(:not(.platform-mac).-theme-with-dark-background) ::-webkit-scrollbar-track {
     -webkit-box-shadow: inset 0 0 1px rgba(255,255,255,0.3);
 }
 
 :not(.platform-mac).-theme-with-dark-background ::-webkit-scrollbar-thumb,
-:host-context(:not(.platform-mac).-theme-with-dark-background) .-theme-with-dark-background ::-webkit-scrollbar-thumb {
+:host-context(:not(.platform-mac).-theme-with-dark-background) ::-webkit-scrollbar-thumb {
     border-radius: 2px;
     background-color: #333;
     -webkit-box-shadow: inset 0 0 1px rgba(255,255,255,0.5);
 }
 
 .gray-info-message {
     text-align: center;
     font-style: italic;
     padding: 6px;
     color: #888;
@@ skipping 53 matching lines @@
     background-color: white;
 }
 
 .force-white-icons .spritesheet-largeicons, .force-white-icons.spritesheet-largeicons {
     -webkit-mask-image: -webkit-image-set(url(Images/toolbarButtonGlyphs.png) 1x, url(Images/toolbarButtonGlyphs_2x.png) 2x);
     -webkit-mask-size: 352px 168px;
     background-image: unset;
     background-size: unset;
     background-color: white;
 }