diff --git a/mozilla/xpfe/appshell/public/nsIXULWindow.idl b/mozilla/xpfe/appshell/public/nsIXULWindow.idl
index 954920e8009..a7b4339682e 100644
--- a/mozilla/xpfe/appshell/public/nsIXULWindow.idl
+++ b/mozilla/xpfe/appshell/public/nsIXULWindow.idl
@@ -96,6 +96,11 @@ interface nsIXULWindow : nsISupports
 
   readonly attribute unsigned long zlevel;
 
+  /**
+   * contextFlags are from nsIWindowCreator2
+   */
+           attribute PRUint32  contextFlags;
+
   /**
   Create a new window.
   @param aChromeFlags: see nsIWebBrowserChrome
diff --git a/mozilla/xpfe/appshell/src/nsXULWindow.cpp b/mozilla/xpfe/appshell/src/nsXULWindow.cpp
index 2464c660f1d..94f8d4511bb 100644
--- a/mozilla/xpfe/appshell/src/nsXULWindow.cpp
+++ b/mozilla/xpfe/appshell/src/nsXULWindow.cpp
@@ -104,7 +104,7 @@ nsXULWindow::nsXULWindow() : mChromeTreeOwner(nsnull),
    mShowAfterLoad(PR_FALSE), mIntrinsicallySized(PR_FALSE),
    mCenterAfterLoad(PR_FALSE), mIsHiddenWindow(PR_FALSE),
    mHadChildWindow(PR_FALSE),
-   mZlevel(nsIXULWindow::normalZ)
+   mZlevel(nsIXULWindow::normalZ), mContextFlags(0)
 {
   NS_INIT_ISUPPORTS();
 }
@@ -185,6 +185,22 @@ NS_IMETHODIMP nsXULWindow::GetZlevel(PRUint32 *outLevel)
    return NS_OK;
 }
 
+NS_IMETHODIMP nsXULWindow::GetContextFlags(PRUint32 *aContextFlags)
+{
+  NS_ENSURE_ARG_POINTER(aContextFlags);
+  *aContextFlags = mContextFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsXULWindow::SetContextFlags(PRUint32 aContextFlags)
+{
+  mContextFlags = aContextFlags;
+  if(mContentTreeOwner)
+    mContentTreeOwner->ApplyChromeFlags();
+
+  return NS_OK;
+}
+
 NS_IMETHODIMP nsXULWindow::SetIntrinsicallySized(PRBool aIntrinsicallySized)
 {
    mIntrinsicallySized = aIntrinsicallySized;
diff --git a/mozilla/xpfe/appshell/src/nsXULWindow.h b/mozilla/xpfe/appshell/src/nsXULWindow.h
index 6507a486acf..de09e606804 100644
--- a/mozilla/xpfe/appshell/src/nsXULWindow.h
+++ b/mozilla/xpfe/appshell/src/nsXULWindow.h
@@ -125,7 +125,8 @@ protected:
    PRPackedBool            mCenterAfterLoad;
    PRPackedBool            mIsHiddenWindow;
    PRPackedBool            mHadChildWindow;
-   unsigned long           mZlevel;
+   PRUint32                mZlevel;
+   PRUint32                mContextFlags;
 };
 
 // nsContentShellInfo