Backout 4e195dd3a989 (bug 767835) for mochitest-browser-chrome failures

browser/base/content/browser.js

@@ -7131,10 +7131,6 @@ let gPrivateBrowsingUI = {
       !this.privateBrowsingEnabled;
   },
 
-  get autoStarted() {
-    return this._privateBrowsingService.autoStarted;
-  },
-
   get privateBrowsingEnabled() {
     return this._privateBrowsingService.privateBrowsingEnabled;
   },

browser/base/content/utilityOverlay.js

@@ -12,9 +12,7 @@ XPCOMUtils.defineLazyGetter(this, "BROWSER_NEW_TAB_URL", function () {
   const TOPIC = "private-browsing-transition-complete";
 
   function getNewTabPageURL() {
-    if (("gPrivateBrowsingUI" in window) &&
-        gPrivateBrowsingUI.privateWindow &&
-        !gPrivateBrowsingUI.autoStarted)
+    if (("gPrivateBrowsingUI" in window) && gPrivateBrowsingUI.privateWindow)
       return "about:privatebrowsing";
     else
       return Services.prefs.getCharPref(PREF) || "about:blank";