We end up hitting this assertion in content/html/document/test/test_bug391777.html: ###!!! ASSERTION: attempted to open a new window with no WindowCreator: 'mWindowCreator', file /Users/jdm/src/mobilebase/embedding/components/windowwatcher/src/nsWindowWatcher.cpp, line 687 We're trying to create a modal chrome window with no chrome parent, and the parent has a null result from GetMainWidget (see nsWindowWatcher::OpenWindowJSInternal).

In fact, the parentWindow is just an nsDocShellTreeOwner and GetMainWidget just returns NS_ERROR_NULL_POINTER.

It looks like the main problem here is that we don't initialize the window watcher component at startup by calling SetWindowCreator as it states we need to in the docs.

Front-end folk, is this something we should be able to do?

Related to bug 753555.

Marking a bunch of bugs in the "Embedding: APIs" component INCOMPLETE in preparation to archive that component. If I have done this incorrectly, please reopen the bugs and move them to a more correct component as we don't have "embedding" APIs any more.