Issue 5973 - broken icons on Firefox v50-53

skin/desktop-options.css

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 192 matching lines @@
   height: 1.3rem;
 }
 
 button[role="checkbox"][disabled].toggle
 {
   background-image: none;
 }
 
 button.delete::before
 {
-  -webkit-mask: url(icons/trash.svg);
-  mask: url(icons/trash.svg);
+  background-image: url(icons/trash.svg#default);
+}
+
+button.delete:hover::before
+{
+  background-image: url(icons/trash.svg#hover);
 }
 
 button.gear::before
 {
-  -webkit-mask: url(icons/gear.svg);
-  mask: url(icons/gear.svg);
+  background-image: url(icons/gear.svg#default);
+}
+
+button.gear:hover::before
+{
+  background-image: url(icons/gear.svg#hover);
 }
 
 button.gear,
 button.delete
 {
   border: 0px;
   padding: 0px;
   background-color: transparent;
 }
 
 button.gear::before,
 button.delete::before
 {
   content: "";
   display: block;
   height: 1.9rem;
   width: 1.9rem;
-  background-color: #099DD1;
-}
-
-button.gear:hover::before,
-button.delete:hover::before
-{
-  background-color: #5CBCE1;
 }
 
 button.link,
 button.list
 {
   color: #099CD0;
 }
 
 button.link
 {
@@ skipping 114 matching lines @@
 
 html[dir="rtl"] [data-validation] .floating-input input:focus:invalid ~ .attention::before,
 html[dir="rtl"] [data-validation] .floating-input input:valid ~ .attention::before
 {
   left: 0rem;
   right: auto;
 }
 
 [data-validation] .floating-input input:focus:invalid ~ .attention::before
 {
-  background-color: #C11D27;
-  -webkit-mask: url(icons/attention.svg);
-  mask: url(icons/attention.svg);
+  background-image: url(icons/attention.svg);
 }
 
 [data-validation] .floating-input input:valid ~ .attention::before
 {
   top: 0.8rem;
-  background-color: green;
-  -webkit-mask: url(icons/checkmark.svg);
-  mask: url(icons/checkmark.svg);
+  background-image: url(icons/checkmark.svg#approved);
 }
 
 [data-validation] .floating-input input ~ .error-msg
 {
   margin-top: 0.5rem;
   color: #C11D27;
   display: block;
   visibility: hidden;
 }
 
@@ skipping 466 matching lines @@
 #dialog .table.list li button[aria-checked="true"]
 {
   color: #BBB;
 }
 
 #dialog .table.list li button[aria-checked="true"]::before
 {
   content: "";
   width: 1.3rem;
   height: 1.3rem;
-  background-color: #BBB;
-  -webkit-mask: url(icons/checkmark.svg);
-  mask: url(icons/checkmark.svg);
+  background-image: url(icons/checkmark.svg#default);
   margin: 0rem;
 }
 
 #dialog .table.list li button .display
 {
   flex: none;
   margin: 0rem 0.8rem;
   text-transform: none;
 }
 
@@ skipping 12 matching lines @@
   text-decoration: none;
   cursor: help;
 }
 
 .tooltip::before
 {
   content: "";
   width: 1.3rem;
   height: 1.3rem;
   display: block;
-  background-color: #099DD1;
-  -webkit-mask: url(icons/tooltip.svg);
-  mask: url(icons/tooltip.svg);
+  background-image: url(icons/tooltip.svg);
 }
 
 /* 
   Used for translatable screen reader only conten.
   e.g.: Use instead of aria-label to avoid complex attribute value translation
 */
 .sr-only
 {
   position: absolute;
   overflow: hidden;
@@ skipping 247 matching lines @@
 {
   background-color: #E1F2FA;
   cursor: pointer;
 }
 
 .context-menu li[role="menuitem"] > *::before
 {
   content: "";
   height: 1.5rem;
   width: 1.5rem;
-  background-color: #099DD1;
   margin: 0rem 1.1rem;
 }
 
 .context-menu .update-subscription::before
 {
-  -webkit-mask: url(icons/reload.svg);
-  mask: url(icons/reload.svg);
+  background-image: url(icons/reload.svg);
 }
 
 .context-menu .website::before
 {
-  -webkit-mask: url(icons/globe.svg);
-  mask: url(icons/globe.svg);
+  background-image: url(icons/globe.svg);
 }
 
 .context-menu .source::before
 {
-  -webkit-mask: url(icons/code.svg);
-  mask: url(icons/code.svg);
+  background-image: url(icons/code.svg);
 }
 
 .context-menu .delete::before
 {
-  -webkit-mask: url(icons/trash.svg);
-  mask: url(icons/trash.svg);
+  background-image: url(icons/trash.svg#default);
 }
 
 /*
   Help tab content
 */
 
 html:not([lang="zh"]) #social-chinese,
 html[lang="zh"] #social-general
 {
   display: none;
@@ skipping 18 matching lines @@
   text-align: center;
 }
 
 #social ul li a::before
 {
   display: block;
   margin: 0em auto;
   width: 2.5rem;
   height: 2.5rem;
   content: "";
-  background-color: #099DD1;
 }
 
 #twitter::before
 {
-  -webkit-mask: url("social/twitter.svg");
-  mask: url("social/twitter.svg");
+  background-image: url("social/twitter.svg");
 }
 
 #facebook::before
 {
-  -webkit-mask: url("social/facebook.svg");
-  mask: url("social/facebook.svg");
+  background-image: url("social/facebook.svg");
 }
 
 #google-plus::before
 {
-  -webkit-mask: url("social/googleplus.svg");
-  mask: url("social/googleplus.svg");
+  background-image: url("social/googleplus.svg");
 }
 
 /*
   Dialog
 */
 
 #dialog-background
 {
   display: none;
   position: fixed;
@@ skipping 49 matching lines @@
 }
 
 #dialog-close::before,
 #hide-notification::after
 {
   content: "";
   display: block;
   height: 1rem;
   width: 1rem;
   border: 0rem;
-  background-color: #FFF;
-  -webkit-mask: url(icons/delete.svg);
-  mask: url(icons/delete.svg);
+  background-image: url(icons/delete.svg#primary);
 }
 
 #dialog-close:hover::before
 {
-  background-color: #000;
+  background-image: url(icons/delete.svg#primary-hover);
 }
 
 #dialog #dialog-body
 {
   max-height: 60vh;
   overflow: auto;
 }
 
 .dialog-content
 {
@@ skipping 101 matching lines @@
   text-align: center;
 }
 
 #hide-notification
 {
   margin: 0rem 1rem;
 }
 
 #hide-notification::after
 {
-  background-color: #099DD1;
+  background-image: url(icons/delete.svg#secondary);
 }
 
 #hide-notification:hover::after
 {
-  background-color: #5CBCE1;
+  background-image: url(icons/delete.svg#secondary-hover);
 }