GitLab

This provides support for type="chrome_messages_json_gzip" in
grit/build.py, which compresses the output files (which should have
.gz appended to the name, e.g. messages.json.gz).

This makes it fairly simple to convert an extension (e.g. chromevox)
to use compressed l10n files.

Original CL:
https://chromium-review.googlesource.com/c/chromium/src/+/1913610

For changes reviewed in the original CL:
TBR=agrieve@chromium.org
TBR=dtseng@chromium.org
TBR=rdevlin.cronin@chromium.org

Bug: 1023568
Change-Id: I7f83e5de8e339aea2e47b84f3ec701350246b38d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1947386Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#720779}