Function FREAcquireNativeWindowHandle 

pub unsafe extern "C" fn FREAcquireNativeWindowHandle(
    nativeWindow: FREObject,
    handle: *mut FRENativeWindow,
) -> FREResult

Referenced handle is valid only for duration of the call to a registered function.

@return FREResult::FRE_OK FREResult::FRE_TYPE_MISMATCH FREResult::FRE_INVALID_OBJECT FREResult::FRE_INVALID_ARGUMENT FREResult::FRE_WRONG_THREAD FREResult::FRE_ILLEGAL_STATE