chromeos-base: Move pkg_postinst to pkg_preinst.
When pkg_postinst fails, portage doesn't know that anything went wrong
and proceeds, but this leaves the SDK in a non-functioning state. Move
the logic into pkg_preinst where failures will be treated as a merge
failure. This would have caught things like crbug.com/757147 much
sooner.
BUG=chromium:756240
TEST=Sent to chomiumos-sdk trybot.
Change-Id: I3a83ec1aa5b7a1014a2c1a770208fc2dc16ba9b0
Reviewed-on: https://chromium-review.googlesource.com/644096
Commit-Ready: Benjamin Gordon <bmgordon@chromium.org>
Tested-by: Benjamin Gordon <bmgordon@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed
