cbuildbot_launch: Move repo cleanup into CleanBuildroot.
Move all cleanup code into CleanBuildroot. We were doing some cleanup
during the InitialCheckout stage, and wiping the buildroot if that
failed. This meant we had multiple locations that could clobber the
buildroot, and we didn't always preserve the buildroot version number
we needed to preserve, which could get us into a clobber root.
BUG=chromium:725598
TEST=Unittests
Change-Id: I345ee739b141b55ac7bec8171a09bd8b40347673
Reviewed-on: https://chromium-review.googlesource.com/513166
Tested-by: Don Garrett <dgarrett@chromium.org>
Trybot-Ready: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Ningning Xia <nxia@chromium.org>
Commit-Queue: Don Garrett <dgarrett@chromium.org>
2 files changed
