a230f424cf
DONTBUILD because this is just whitespace cleanup.
I found the files to fix up here using this command:
grep -r ' ' * 2>/dev/null | grep -v "other-licenses" | grep "idl:"
I replaced the tab characters with however many spaces seemed consistent with
the indentation in the surrounding code (and did some minor space-indentation
cleanup in contextual lines to preserve alignment, in a few cases).
Differential Revision: https://phabricator.services.mozilla.com/D160577