DevTools: Replace Apple styled spinner icon with Chromium one.

Source/devtools/front_end/inspector.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 2035 matching lines @@
 }
 
 .sidebar-tree-item .icon {
     float: left;
     width: 32px;
     height: 32px;
     margin-top: 1px;
     margin-right: 3px;
 }
 
+.sidebar-tree-item.wait .icon {
+    content: none;
+}
+
+.spinner-icon::before,
+.sidebar-tree-item.wait .icon::before {
+    display: block;
+    width: 24px;
+    height: 24px;
+    margin: 4px;
+    border: 3px solid grey;
+    border-radius: 12px;
+    clip: rect(0px, 15px, 15px, 0px);
+    content: "";
+    position: absolute;
+    -webkit-animation: spinner-animation 1s linear infinite;
+}
+
+.spinner-icon.small::before,
+.sidebar-tree-item.wait.small .icon::before {
+    width: 14px;
+    height: 14px;
+    margin: 1px;
+    clip: rect(0px, 9px, 9px, 0px);
+    border-width: 2px;
+}
+
+.sidebar-tree-item.wait.selected .icon::before {
+    border-color: white;
+}
+
+@-webkit-keyframes spinner-animation {
+    from { -webkit-transform: rotate(0); }
+    to { -webkit-transform: rotate(360deg); }
+}
+
 li .status {
     float: right;
     height: 16px;
     margin-top: 9px;
     margin-left: 4px;
     line-height: 1em;
 }
 
 li .status:empty {
     display: none;
@@ skipping 771 matching lines @@
     padding-left: 2px;
 }
 
 body.undocked .toolbar-close-button-item {
     display: none;
 }
 
 .root-view > .split-view > .split-view-sidebar {
     position: relative;
 }