Add the npapi_test_plugin to the Mac build of test_shell

webkit/glue/plugins/test/plugin_javascript_open_popup.cc

Index: webkit/glue/plugins/test/plugin_javascript_open_popup.cc
===================================================================
--- webkit/glue/plugins/test/plugin_javascript_open_popup.cc	(revision 14732)
+++ webkit/glue/plugins/test/plugin_javascript_open_popup.cc	(working copy)
@@ -95,6 +95,12 @@
 
   return false;
 }
+#elif defined(OS_MACOSX)
+bool ExecuteJavascriptPopupWindowTargetPluginTest::CheckWindow(
+    NPWindow* window) {
+  // TODO(port) scaffolding--replace with a real test once NPWindow is done.
+  return false;
+}
 #endif
 
 } // namespace NPAPIClient