libchromeos: Move url_utils from Buffet to libchromeos BUG=chromium:405714 TEST=USE=buffet ./build_packages Change-Id: Ia46f88ca2e684e37688fb2ab43c258cda95e44c3 Reviewed-on: https://chromium-review.googlesource.com/213363 Tested-by: Alex Vakulenko <avakulenko@chromium.org> Reviewed-by: Bertrand Simonnet <bsimonnet@chromium.org> Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>