This was preventing https://ubereats.com/ from fully loading, because
they are attempting to overwrite setItem. They seem to be trying to add
error logging to setItem if it throws, as all they do is add a
try/catch block that emits an error log to their monitoring service if
it throws.
However, because Storage is a legacy platform object with a named
property setter (setItem), it will call setItem with the stringified
version of the function. This is actually expected as per the spec,
Firefox (Gecko) and Epiphany (WebKit) does this too, but Chromium does
not as it actually overwrites the function with the new function and
does not store the stringified function.
The problem is that we had the LegacyOverrideBuiltIns flag accidentally
set, so it would return the stored string instead of the built-in
function (hence the name), then it would try and call it and throw a
"not a function" error. This prevented their JS from going any further.
This fix allows their UI to fully load and be fully interactive, though
it is quite slow at the moment!
