DevTools: set a default color for icon masks

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 309 matching lines @@
     font-size: 13px;
     overflow: auto;
     z-index: 500;
 }
 
 [is=ui-icon] {
     display: inline-block;
     flex-shrink: 0;
 }
 
+.icon-mask {
+    background-color: rgb(110, 110, 110);
+}
+
 .spritesheet-smallicons {
     background-image: -webkit-image-set(url(Images/smallIcons.png) 1x, url(Images/smallIcons_2x.png) 2x);
     background-size: 190px 30px;
 }
 
 .spritesheet-smallicons.icon-mask {
     -webkit-mask-image: -webkit-image-set(url(Images/smallIcons.png) 1x, url(Images/smallIcons_2x.png) 2x);
     -webkit-mask-size: 190px 30px;
 }
 
@@ skipping 15 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;
 }