Bug 1355661 added support for brotli streams in "jar" files handled by
Gecko, and bug 1355671 made us build the `bro` command line utility that
allows to compress and decompress brotli streams.
This change uses the `bro` command line utility in the packager so that
it can create and handle "jar" files using brotli streams.
However, the `bro` command line utility is not available to l10n
repacks. As, at the moment, we're only hoping that the outcome of using
brotli will be good, we avoid doing all the work to make those work and
just hook things enough to enable brotli, while ensuring l10n repacks
don't break. This involves forcing some files to be deflated, and to
disable some optimizations from the packager.
Things will need to be figured out more properly if the experiment
proves brotli to be worthwhile.
--HG--
extra : rebase_source : a2e0cff67dcaed465fd441ed5d2a7de94b6351c5