libchromeos: Move mime_utils from Buffet to libchromeos

BUG=chromium:405714
TEST=USE=buffet ./build_packages

Change-Id: I4e0bf9600aedda9a9ac913a1234ab1b20da72777
Reviewed-on: https://chromium-review.googlesource.com/213364
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: Bertrand Simonnet <bsimonnet@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
11 files changed
tree: 785486ef399dda06a37220aeb8e3702e806799f4
  1. buffet/