diff --git a/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp b/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
index 46bc6767727..bc149a4ac0c 100644
--- a/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
+++ b/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
@@ -1127,6 +1127,12 @@ nsBrowserWindow::GetStatus(PRUnichar** aResult)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsBrowserWindow::SetProgress(PRInt32 aProgress, PRInt32 aProgressMax)
+{
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsBrowserWindow::WillLoadURL(nsIWebShell* aShell, const PRUnichar* aURL, nsLoadType aReason)
 {
diff --git a/mozilla/webshell/tests/viewer/nsBrowserWindow.h b/mozilla/webshell/tests/viewer/nsBrowserWindow.h
index b1ad7fbfa2b..40e1a117984 100644
--- a/mozilla/webshell/tests/viewer/nsBrowserWindow.h
+++ b/mozilla/webshell/tests/viewer/nsBrowserWindow.h
@@ -78,6 +78,7 @@ public:
   NS_IMETHOD GetTitle(PRUnichar** aResult);
   NS_IMETHOD SetStatus(const PRUnichar* aStatus);
   NS_IMETHOD GetStatus(PRUnichar** aResult);
+  NS_IMETHOD SetProgress(PRInt32 aProgress, PRInt32 aProgressMax);
   NS_IMETHOD GetWebShell(nsIWebShell*& aResult);
 
   // nsIStreamObserver