Issue 5980 - Use correct browser logos for browser select on help.eyeo.com

static/scss/components/_browser-select.scss

 // This file is part of help.eyeo.com.
 // Copyright (C) 2017 Eyeo GmbH
 //
 // help.eyeo.com is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
 // the Free Software Foundation, either version 3 of the License, or
 // (at your option) any later version.
 //
 // help.eyeo.com is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 19 matching lines @@
 {
   display: inline-block;
   width: 100%;
   max-width: 300px;
 }
 
 #browser-select li
 {
   cursor: pointer;
 }
+
+#browser-select .pre-icon
+{
+  opacity: 0.5;
+
+  /* Firefox 10+, Firefox on Android */
+  filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'1 0 0 0 0, 0 1 0 0 0, 0 0 1 0 0, 0 0 0 1 0\'/></filter></svg>#grayscale");
+
+  /* IE 6-9 */
+  filter: gray;
+  
+  /* Modern browsers */
+  filter: grayscale(100%);
+}
+
+#browser-select .custom-select-selected .pre-icon,
+#browser-select .custom-select-option:hover .pre-icon,
+#browser-select .custom-select-option:focus .pre-icon
+{
+  opacity: 1;
+  filter: none;
+}