Fix relative file: paths in OWNERS with roots other than '/'

Fix relative file: paths in OWNERS with roots other than '/'

If an OWNERS file used the file: directive with a relative file
path, but was using a root other than '/' (e.g.
'/path/to/my/real/root'), then the include resolver would incorrectly
leave a leading '/' on the include path. When os_path.join was then
called, the leading '/' meant the path was treated as an absolute path
and the join did not behave as expected.

Committed: https://chromium.googlesource.com/chromium/tools/depot_tools/+/f2d73522b8d989a4a325ddefdf4dc88f39eaeedb

[mbjorge, 2016-07-13 18:09:27]

mbjorge@chromium.org changed reviewers:
+ dpranke@chromium.org

[Dirk Pranke, 2016-07-14 19:16:00]

lgtm

[mbjorge, 2016-07-14 20:25:19]

The CQ bit was checked by mbjorge@chromium.org

[commit-bot: I haz the power, 2016-07-14 20:25:25]

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, 2016-07-14 20:29:02]

Description was changed from

==========
Fix relative file: paths in OWNERS with roots other than '/'

If an OWNERS file used the file: directive with a relative file
path, but was using a root other than '/' (e.g.
'/path/to/my/real/root'), then the include resolver would incorrectly
leave a leading '/' on the include path. When os_path.join was then
called, the leading '/' meant the path was treated as an absolute path
and the join did not behave as expected.
==========

to

==========
Fix relative file: paths in OWNERS with roots other than '/'

If an OWNERS file used the file: directive with a relative file
path, but was using a root other than '/' (e.g.
'/path/to/my/real/root'), then the include resolver would incorrectly
leave a leading '/' on the include path. When os_path.join was then
called, the leading '/' meant the path was treated as an absolute path
and the join did not behave as expected.

Committed:
https://chromium.googlesource.com/chromium/tools/depot_tools/+/f2d73522b8d989...
==========

[commit-bot: I haz the power, 2016-07-14 20:29:02]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/tools/depot_tools/+/f2d73522b8d989...