Bug 963512 - use real element for Australis private browsing indicator to avoid layout issues with detecting ::after, r=dao

browser/base/content/browser.xul

@@ -592,6 +592,9 @@
                      cui-areatype="toolbar"
                      tooltiptext="&closeTab.label;"/>
 
+#ifdef XP_WIN
+      <hbox id="private-browsing-indicator" skipintoolbarset="true" ordinal="1000"/>
+#endif
 #ifdef CAN_DRAW_IN_TITLEBAR
       <hbox class="titlebar-placeholder" type="caption-buttons"
             id="titlebar-placeholder-on-TabsToolbar-for-captions-buttons" persist="width"

browser/themes/windows/browser.css

@@ -2509,9 +2509,7 @@ chatbox {
 
 /* End customization mode */
 
-#main-window[privatebrowsingmode=temporary] #TabsToolbar::after {
-  content: "";
-  display: -moz-box;
+#main-window[privatebrowsingmode=temporary] #private-browsing-indicator {
   width: 40px;
   background: url("chrome://browser/skin/privatebrowsing-indicator.png") no-repeat center center;
 }