https://bugs.winehq.org/show_bug.cgi?id=37585
--- Comment #13 from Erich E. Hoover erich.e.hoover@wine-staging.com --- (In reply to Anastasius Focht from comment #12)
... Reading the Chromium project change history it seems the WoW helper process mechanism is only supported/implemented for OS <= Windows Vista anyway.
--- quote --- fixing this is looking like a real mess. --- quote ---
I tend to say "not worth the damage". At one point Wine will default to Winver "Windows 7" anyway and the sandboxing schemes employ different methods then.
Looks like you're right, the helper processes is only used <=Vista: https://github.com/adobe/chromium/blob/cfe5bf0b51b1f6b9fe239c2a3c2f2364da996...
That possibly gives us an avenue for supporting this without making a giant mess. The 32-bit and WoW64 thunks are not horrible, so with a little digging we may be able to support Win7 mode.