Gabriel Ivăncescu (@insn) commented about dlls/mshtml/mshtml_private.h:
extern HINSTANCE hInst; void create_console(compat_mode_t compat_mode, IWineMSHTMLConsole **ret); HRESULT create_media_query_list(HTMLWindow *window, BSTR media_query, IDispatch **ret); + +void create_mutation_observer(compat_mode_t compat_mode, IDispatch *callback, + IWineMSHTMLMutationObserver **ret); Likewise to prevent confusion I'd rename this to make it known it's a constructor so maybe `create_mutation_observer_ctor`? Also in this case you don't pass the callback when creating the constructor, you pass it when instantiating something from the constructor (but since you make it a stub, you don't need that now).
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/3391#note_39940