Fix walk graph to recurse correctly.

Fix walk graph to recurse correctly.

Previously max depth would be used to see how far to load attempts, as well as
how far to recurse deps. That's pretty silly. Now we use max_depth > 0 to
actually restrict how far down we walk. This makes the API match its documented
behavior in the protos.

R=dnj@chromium.org, vadimsh@chromium.org
BUG=

Committed: https://github.com/luci/luci-go/commit/6ee6d7b70a20e63e1115441a424ddd039d1c6b29

[Vadim Sh., 2016-09-17 00:01:10]

lgtm

[iannucci, 2016-09-17 00:06:03]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2016-09-17 00:06:12]

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, 2016-09-17 00:14:48]

Description was changed from

==========
Fix walk graph to recurse correctly.

Previously max depth would be used to see how far to load attempts, as well as
how far to recurse deps. That's pretty silly. Now we use max_depth > 0 to
actually restrict how far down we walk. This makes the API match its documented
behavior in the protos.

R=dnj@chromium.org, vadimsh@chromium.org
BUG=
==========

to

==========
Fix walk graph to recurse correctly.

Previously max depth would be used to see how far to load attempts, as well as
how far to recurse deps. That's pretty silly. Now we use max_depth > 0 to
actually restrict how far down we walk. This makes the API match its documented
behavior in the protos.

R=dnj@chromium.org, vadimsh@chromium.org
BUG=

Committed:
https://github.com/luci/luci-go/commit/6ee6d7b70a20e63e1115441a424ddd039d1c6b29
==========

[commit-bot: I haz the power, 2016-09-17 00:14:49]

Committed patchset #1 (id:1) as
https://github.com/luci/luci-go/commit/6ee6d7b70a20e63e1115441a424ddd039d1c6b29