isolate: clean up some path handling

isolate: clean up some path handling in directory walking code.

BUG=692940
Review-Url: https://codereview.chromium.org/2980233003
Committed: https://github.com/luci/luci-go/commit/c73a01793deb23192570c36c44c1a3978d4eb0db

[mcgreevy, 2017-07-18 01:45:19]

mcgreevy@chromium.org changed reviewers:
+ tansell@chromium.org

[mcgreevy, 2017-07-18 01:45:19]

I'm splitting this out of a larger refactoring, to make it easier to review.

[mithro, 2017-07-18 02:28:18]

LGTM.

Nit: The subject / commit message could be better :-).

[mcgreevy, 2017-07-18 03:46:46]

Description was changed from

==========
isolate: clean up some path handling

BUG=692940
==========

to

==========
isolate: clean up some path handling in directory walking code.

BUG=692940
==========

[mcgreevy, 2017-07-18 03:46:55]

The CQ bit was checked by mcgreevy@chromium.org

[commit-bot: I haz the power, 2017-07-18 03:47:05]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-07-18 03:53:15]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1500349615717210,
"parent_rev": "b6f50320fa6dcc98867278fa297b5c4a300c026e", "commit_rev":
"c73a01793deb23192570c36c44c1a3978d4eb0db"}

[commit-bot: I haz the power, 2017-07-18 03:53:18]

Description was changed from

==========
isolate: clean up some path handling in directory walking code.

BUG=692940
==========

to

==========
isolate: clean up some path handling in directory walking code.

BUG=692940

Review-Url: https://codereview.chromium.org/2980233003
Committed:
https://github.com/luci/luci-go/commit/c73a01793deb23192570c36c44c1a3978d4eb0db
==========

[commit-bot: I haz the power, 2017-07-18 03:53:19]

Committed patchset #2 (id:20001) as
https://github.com/luci/luci-go/commit/c73a01793deb23192570c36c44c1a3978d4eb0db