--- a/browser/base/content/tabview/ui.js
+++ b/browser/base/content/tabview/ui.js
@@ -95,21 +95,19 @@ let UI = {
   // Constant: _maxInteractiveWait
   // If the UI is in the middle of an operation, this is the max amount of
   // milliseconds to wait between input events before we no longer consider
   // the operation interactive.
   _maxInteractiveWait: 250,
 
   // Variable: _privateBrowsing
   // Keeps track of info related to private browsing, including: 
-  //   transitionStage - what step we're on in entering/exiting PB
   //   transitionMode - whether we're entering or exiting PB
   //   wasInTabView - whether TabView was visible before we went into PB
   _privateBrowsing: {
-    transitionStage: 0,
     transitionMode: "",
     wasInTabView: false 
   },
 
   // ----------
   // Function: init
   // Must be called after the object is created.
   init: function UI_init() {
@@ -520,75 +518,66 @@ let UI = {
     // session restore
     function srObserver(aSubject, aTopic, aData) {
       if (aTopic != "sessionstore-browser-state-restored")
         return;
         
       let hasGroupItemsData = GroupItems.load();
       if (!hasGroupItemsData)
         self.reset(false);
-        
-      // if we're transitioning into/out of private browsing, update appropriately
-      if (self._privateBrowsing.transitionStage == 1)
-        self._privateBrowsing.transitionStage = 2;
-      else if (self._privateBrowsing.transitionStage == 3) {
-        if (self._privateBrowsing.transitionMode == "exit" &&
-            self._privateBrowsing.wasInTabView)
-          self.showTabView(false);
-
-        self._privateBrowsing.transitionStage = 0;
-        self._privateBrowsing.transitionMode = "";
-        TabItems.resumeReconnecting();
-        GroupItems.resumeUpdatingTabBar();
-      }
     }
 
     Services.obs.addObserver(srObserver, "sessionstore-browser-state-restored", false);
 
     this._cleanupFunctions.push(function() {
       Services.obs.removeObserver(srObserver, "sessionstore-browser-state-restored");
     });
 
     // Private Browsing:
-    // We keep track of the transition to/from PB with the transitionStage
-    // and transitionMode properties of _privateBrowsing. The stage is 0 if
-    // not transitioning, 1 if just started ("change-granted"), 2 after the
-    // first sessionrestore, 3 after the "private-browsing" notification, and
-    // then back to 0 after the second sessionrestore. The mode is "" if not
-    // transitioning, otherwise it's "enter" or "exit" as appropriate. When
-    // transitioning to PB, we exit Panorama if necessary (making note of the
+    // When transitioning to PB, we exit Panorama if necessary (making note of the
     // fact that we were there so we can return after PB) and make sure we
     // don't reenter Panorama due to all of the session restore tab
     // manipulation (which otherwise we might). When transitioning away from
     // PB, we reenter Panorama if we had been there directly before PB.
     function pbObserver(aSubject, aTopic, aData) {
       if (aTopic == "private-browsing") {
-        self._privateBrowsing.transitionStage = 3;
+        // We could probably do this in private-browsing-change-granted, but
+        // this seems like a nicer spot, right in the middle of the process.
         if (aData == "enter") {
           // If we are in Tab View, exit. 
           self._privateBrowsing.wasInTabView = self.isTabViewVisible();
           if (self.isTabViewVisible())
             self.goToTab(gBrowser.selectedTab);
         }
       } else if (aTopic == "private-browsing-change-granted") {
         if (aData == "enter" || aData == "exit") {
-          self._privateBrowsing.transitionStage = 1;
           self._privateBrowsing.transitionMode = aData;
           GroupItems.pauseUpdatingTabBar();
           TabItems.pauseReconnecting();
         }
+      } else if (aTopic == "private-browsing-transition-complete") {
+        // We use .transitionMode here, as aData is empty.
+        if (self._privateBrowsing.transitionMode == "exit" &&
+            self._privateBrowsing.wasInTabView)
+          self.showTabView(false);
+
+        self._privateBrowsing.transitionMode = "";
+        TabItems.resumeReconnecting();
+        GroupItems.resumeUpdatingTabBar();
       }
     }
 
     Services.obs.addObserver(pbObserver, "private-browsing", false);
     Services.obs.addObserver(pbObserver, "private-browsing-change-granted", false);
+    Services.obs.addObserver(pbObserver, "private-browsing-transition-complete", false);
 
     this._cleanupFunctions.push(function() {
       Services.obs.removeObserver(pbObserver, "private-browsing");
       Services.obs.removeObserver(pbObserver, "private-browsing-change-granted");
+      Services.obs.removeObserver(pbObserver, "private-browsing-transition-complete");
     });
 
     // TabOpen
     this._eventListeners.open = function(tab) {
       if (tab.ownerDocument.defaultView != gWindow)
         return;
 
       // if it's an app tab, add it to all the group items
@@ -607,17 +596,17 @@ let UI = {
         
       if (self.isTabViewVisible()) {
         // just closed the selected tab in the TabView interface.
         if (self._currentTab == tab)
           self._closedSelectedTabInTabView = true;
       } else {
         // If we're currently in the process of entering private browsing,
         // we don't want to go to the Tab View UI. 
-        if (self._privateBrowsing.transitionStage > 0)
+        if (self._privateBrowsing.transitionMode)
           return; 
           
         // if not closing the last tab
         if (gBrowser.tabs.length > 1) {
           // Don't return to TabView if there are any app tabs
           for (let a = 0; a < gBrowser.tabs.length; a++) {
             let theTab = gBrowser.tabs[a]; 
             if (theTab.pinned && gBrowser._removingTabs.indexOf(theTab) == -1)