Issue 384 - Wrong image shows up briefly for Adblock Plus icon

lib/ui.js

Index: lib/ui.js
===================================================================
--- a/lib/ui.js
+++ b/lib/ui.js
@@ -407,30 +407,32 @@ let UI = exports.UI =
       {
         ({CustomizableUI}) = Cu.import("resource:///modules/CustomizableUI.jsm", null);
       }
       catch (e)
       {
         // No built-in CustomizableUI API, use our own implementation.
         ({CustomizableUI}) = require("customizableUI");
       }
-      
+
       CustomizableUI.createWidget({
         id: "abp-toolbarbutton",
         type: "custom",
         positionAttribute: "abp-iconposition",        // For emulation only
         defaultArea: defaultToolbarPosition.parent,
         defaultBefore: defaultToolbarPosition.before, // For emulation only
         defaultAfter: defaultToolbarPosition.after,   // For emulation only
         removable: true,
         onBuild: function(document)
         {
           let node = document.importNode(this.overlay["abp-toolbarbutton"], true);
           node.addEventListener("click", this.onIconClick, false);
           node.addEventListener("command", this.onIconClick, false);
+          if ("addClass" in defaultToolbarPosition)
+            node.classList.add(defaultToolbarPosition.addClass);
           this.updateIconState(document.defaultView, node);
           return node;
         }.bind(this),
         onAdded: function(node)
         {
           // For emulation only, this callback isn't part of the official
           // CustomizableUI API.
           this.updateIconState(node.ownerDocument.defaultView, node);