nvda

9afb6fc5 - Remove code to support out-of-process iframes in Firefox which is no longer necessary. (#16746)

Remove code to support out-of-process iframes in Firefox which is no longer necessary. (#16746) Reverts #10707. Summary of the issue: Firefox moved most iframes into different processes (AKA out-of-process iframes or project "Fission") in 2020. This necessitated some changes to NVDA because with Firefox's older multi-process architecture, objects in one process were unaware of objects in another. However, with the new "Cache the World" architecture released in Firefox 113 (just over a year ago in May 2023), this special handling is no longer necessary, since all objects are served from the parent process and the parent process is aware of all of them. While removing this code likely doesn't have any discernible user benefit, I think it's worthwhile to remove unnecessary complexity. There is no supported version of Firefox (even ESR) which depends on this code. Description of user facing changes None. There might be a slight performance benefit, but I doubt this is perceivable. Description of development approach Reverted #10707, adjusting for non-substantive changes that were made since #10707 was merged (code style, moved constants, etc.). Note that this moves back to using accChild instead of getNVDAObjectFromEvent. At the time, there didn't appear to be a performance benefit to using accChild and using getNVDAObjectFromEvent made it easier to implement #10707. However, I have since then discovered (through Firefox profiling) that at least in-process, AccessibleObjectFromWindow can be rather slow relative to direct COM calls. This probably isn't noticeable for NVDA's use case, especially given that we're doing this across processes, but any performance boost is probably worthwhile here. I didn't add a change log entry because there is no user visible change here