Bug 908796 - Workaround to prevent the tabstrip from fully repainting on tab close. r=MattN.

browser/themes/windows/browser.css

@@ -105,9 +105,6 @@
   background-image: linear-gradient(@toolbarHighlight@, rgba(255,255,255,0));
   box-shadow: 0 1px 0 @toolbarHighlight@ inset;
   margin-top: -1px; /* Move up 1px into the TabsToolbar */
-  /* Position the toolbar above the bottom of background tabs */
-  position: relative;
-  z-index: 1;
 }
 
 #widget-overflow-list > .overflowedItem {