Index: Source/WebKit/gtk/webkit/webkitwebview.cpp
===================================================================
--- Source/WebKit/gtk/webkit/webkitwebview.cpp	(revision 164917)
+++ Source/WebKit/gtk/webkit/webkitwebview.cpp	(working copy)
@@ -942,7 +942,11 @@ static void webkit_web_view_size_allocat
     GTK_WIDGET_CLASS(webkit_web_view_parent_class)->size_allocate(widget, allocation);
 
     WebKitWebView* webView = WEBKIT_WEB_VIEW(widget);
-    if (sizeChanged && !gtk_widget_get_mapped(widget)) {
+    bool backingStoreNull = false;
+    if (!webView->priv->backingStore)
+        backingStoreNull = true;
+
+    if ((backingStoreNull || sizeChanged) && !gtk_widget_get_mapped(widget)) {
         webView->priv->needsResizeOnMap = true;
         return;
     }