diff --git a/mozilla/docshell/base/nsDocShell.cpp b/mozilla/docshell/base/nsDocShell.cpp
index 647e666dd50..4bbff9ee07e 100644
--- a/mozilla/docshell/base/nsDocShell.cpp
+++ b/mozilla/docshell/base/nsDocShell.cpp
@@ -1406,6 +1406,16 @@ nsDocShell::TabToTreeOwner(PRBool aForward, PRBool* aTookFocus)
     return NS_OK;
 }
 
+NS_IMETHODIMP
+nsDocShell::Blur()
+{
+  nsCOMPtr<nsIEmbeddingSiteWindow> window = do_GetInterface(mTreeOwner);
+  if (window)
+    return window->Blur();
+  
+  return NS_ERROR_FAILURE;
+}
+
 
 //*****************************************************************************
 // nsDocShell::nsIDocShellTreeItem
diff --git a/mozilla/docshell/base/nsIDocShell.idl b/mozilla/docshell/base/nsIDocShell.idl
index 3871fe4fcc7..2e5bd4ed142 100644
--- a/mozilla/docshell/base/nsIDocShell.idl
+++ b/mozilla/docshell/base/nsIDocShell.idl
@@ -263,6 +263,12 @@ interface nsIDocShell : nsISupports
   void tabToTreeOwner(in boolean forward,
                       out boolean tookFocus);
 
+  /**
+   Tells the docshell to unfocus itself. This is the where nsIDOMWindow::blur
+   comes for its implementation.
+   */
+  void blur();
+
   /**
    * Current busy state for DocShell
    */
diff --git a/mozilla/embedding/browser/webBrowser/nsIEmbeddingSiteWindow.idl b/mozilla/embedding/browser/webBrowser/nsIEmbeddingSiteWindow.idl
index de3c2ed20a0..b14dbbffab1 100644
--- a/mozilla/embedding/browser/webBrowser/nsIEmbeddingSiteWindow.idl
+++ b/mozilla/embedding/browser/webBrowser/nsIEmbeddingSiteWindow.idl
@@ -87,6 +87,11 @@ interface nsIEmbeddingSiteWindow : nsISupports
      */
     void setFocus();
 
+    /**
+     * Blur the window
+     */
+    void blur();
+
     /**
      * Visibility of the window.
      */