Remove all usage of -webkit-*gradient inside blink

Tools/GardeningServer/styles/common.css

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 26 matching lines @@
     color: #333;
 }
 
 .ui-widget-content {
     font-family: 'Open Sans';
 }
 
 .ui-widget button, button {
     font-family: 'Open Sans';
     border-radius: 2px;
-    background-image: -webkit-linear-gradient(top,#f5f5f5,#f1f1f1);
+    background-image: linear-gradient(#f5f5f5, #f1f1f1);
     border: 1px solid rgba(0, 0, 0, 0.1);
     border-radius: 2px;
     color: #666;
     cursor: pointer;
     font-size: 11px;
     font-weight: bold;
     height: 29px;
     line-height: 27px;
     min-width: 54px;
     padding: 0 8px;
     text-align: center
 }
 
 button.next {
     margin-left: 0px;
 }
 
 button.previous {
     margin-right: 0px;
 }
 
 button[disabled] {
     visibility: hidden;
 }
 
 button:hover {
-    background-image: -webkit-linear-gradient(top,#f8f8f8,#f1f1f1);
+    background-image: linear-gradient(#f8f8f8, #f1f1f1);
     -webkit-box-shadow: 0 1px 1px rgba(0,0,0,0.1);
     background-color: #f8f8f8;
     background-image: linear-gradient(top,#f8f8f8,#f1f1f1);
     border: 1px solid #c6c6c6;
     box-shadow: 0 1px 1px rgba(0,0,0,0.1);
     color: #333
 }
 
 button:focus {
     border: 1px solid #4d90fe;
     outline: none
 }
 
 button.default {
     border: 1px solid #3079ED;
     color: white;
-    background-image: -webkit-linear-gradient(top,#4d90fe,#4787ed);
+    background-image: linear-gradient(#4d90fe, #4787ed);
 }
 
 button.default:hover {
     border: 1px solid #2f5bb7;
     color: white;
     background-color: #357ae8;
     background-image: -webkit-gradient(linear,left top,left bottom,from(#4d90fe),to(#357ae8));
 }
 
 .clear {
     clear: both;
 }