diff --git a/browser/app/nsBrowserApp.cpp b/browser/app/nsBrowserApp.cpp
index 0e5d530b33a..1bb81ef8cfe 100644
--- a/browser/app/nsBrowserApp.cpp
+++ b/browser/app/nsBrowserApp.cpp
@@ -191,6 +191,10 @@ static int do_main(int argc, char* argv[], nsIFile *xreDirectory)
       argv[1] = argv[0];
       argv++;
       argc--;
+    } else if (IsArg(argv[1], "BackgroundSessionClosed")) {
+      // This command line flag is used for indirect shutdowns, the OS
+      // relaunches Metro Firefox with this command line arg.
+      mainFlags = XRE_MAIN_FLAG_USE_METRO;
     } else {
       // This command-line flag is used to test the metro browser in a desktop
       // environment.
diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
index a71265f2bdf..8ea8ac12081 100644
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -4028,7 +4028,7 @@ static XREMain* xreMainPtr;
 
 // must be called by the thread we want as the main thread
 nsresult
-XRE_metroStartup()
+XRE_metroStartup(bool runXREMain)
 {
   nsresult rv;
 
@@ -4044,8 +4044,10 @@ XRE_metroStartup()
   rv = xreMainPtr->mScopedXPCom->Initialize();
   NS_ENSURE_SUCCESS(rv, rv);
 
-  rv = xreMainPtr->XRE_mainRun();
-  NS_ENSURE_SUCCESS(rv, rv);
+  if (runXREMain) {
+    rv = xreMainPtr->XRE_mainRun();
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
   return NS_OK;
 }
 
diff --git a/widget/windows/winrt/MetroApp.cpp b/widget/windows/winrt/MetroApp.cpp
index 72a3068df44..22f293dfd60 100644
--- a/widget/windows/winrt/MetroApp.cpp
+++ b/widget/windows/winrt/MetroApp.cpp
@@ -11,6 +11,8 @@
 #include "MetroAppShell.h"
 #include "nsICommandLineRunner.h"
 #include "FrameworkView.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include <shellapi.h>
 
 using namespace ABI::Windows::ApplicationModel;
 using namespace ABI::Windows::ApplicationModel::Core;
@@ -22,7 +24,7 @@ using namespace Microsoft::WRL::Wrappers;
 
 // Metro specific XRE methods we call from here on an
 // appropriate thread.
-extern nsresult XRE_metroStartup();
+extern nsresult XRE_metroStartup(bool runXREMain);
 extern void XRE_metroShutdown();
 
 #ifdef PR_LOGGING
@@ -68,7 +70,7 @@ MetroApp::Initialize()
   if (!xpcomInit) {
     xpcomInit = true;
     Log(L"XPCOM startup initialization began");
-    nsresult rv = XRE_metroStartup();
+    nsresult rv = XRE_metroStartup(true);
     Log(L"XPCOM startup initialization complete");
     if (NS_FAILED(rv)) {
       Log(L"XPCOM startup initialization failed, bailing. rv=%X", rv);
@@ -195,6 +197,17 @@ MetroApp::PostSleepWakeNotification(const bool aIsSleep)
 
 } } }
 
+
+static bool
+IsBackgroundSessionClosedStartup()
+{
+  int argc;
+  LPWSTR *argv = CommandLineToArgvW(GetCommandLineW(), &argc);
+  bool backgroundSessionClosed = argc > 1 && !wcsicmp(argv[1], L"-BackgroundSessionClosed");
+  LocalFree(argv);
+  return backgroundSessionClosed;
+}
+
 bool
 XRE_MetroCoreApplicationRun()
 {
@@ -219,7 +232,28 @@ XRE_MetroCoreApplicationRun()
   }
 
   sFrameworkView = Make<FrameworkView>(sMetroApp.Get());
-  sCoreApp->Run(sMetroApp.Get());
+
+  // Perform any cleanup for unclean shutdowns here, such as when the background session
+  // is closed via the appbar on the left when outside of Metro.  Windows restarts the
+  // process solely for cleanup reasons.
+  if (IsBackgroundSessionClosedStartup() && SUCCEEDED(XRE_metroStartup(false))) {
+
+    // Whether or  not to use sessionstore depends on if the bak exists.  Since host process
+    // shutdown isn't a crash we shouldn't restore sessionstore.
+    nsCOMPtr<nsIFile> sessionBAK;
+    if (NS_FAILED(NS_GetSpecialDirectory("ProfDS", getter_AddRefs(sessionBAK)))) {
+      return false;
+    }
+
+    sessionBAK->AppendNative(nsDependentCString("sessionstore.bak"));
+    bool exists;
+    if (NS_SUCCEEDED(sessionBAK->Exists(&exists)) && exists) {
+      sessionBAK->Remove(false);
+    }
+    return false;
+  }
+
+  hr = sCoreApp->Run(sMetroApp.Get());
 
   Log(L"Exiting CoreApplication::Run");