Explicit registering for load progress to make the Gecko Performance test run again. Patch from ccarlen, r=attinasi

webshell/tests/viewer/nsBrowserWindow.cpp

@@ -1408,6 +1408,7 @@ nsBrowserWindow::Init(nsIAppShell* aAppShell,
   rv = webBrowserWin->InitWindow(mWindow->GetNativeData(NS_NATIVE_WIDGET), nsnull, r.x, r.y, r.width, r.height);
   NS_ENSURE_SUCCESS(EnsureWebBrowserChrome(), NS_ERROR_FAILURE);
   mWebBrowser->SetContainerWindow(mWebBrowserChrome);
+  mWebBrowser->AddWebBrowserListener((nsIWebProgressListener *)(mWebBrowserChrome), NS_GET_IID(nsIWebProgressListener));
 
   webBrowserWin->Create();
   mDocShell = do_GetInterface(mWebBrowser);