[grpc/logging] Update to LoggerV2.

[grpc/logging] Update to LoggerV2.

The gRPC package has released its "LoggerV2" interface, which tries to
maintain backwards compatibility with Logger but fails (see
https://github.com/grpc/grpc-go/issues/1360).

Update our gRPC logging adapter to operate through LoggerV2.

BUG=None
TEST=unit

Review-Url: https://codereview.chromium.org/2976583002
Committed: https://github.com/luci/luci-go/commit/20552da21fbd9b430045c43a86735ff3c8f3cea8

[dnj, 2017-07-08 18:42:28]

The CQ bit was checked by dnj@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-07-08 18:42:35]

Dry run: CQ is trying da patch.

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

[dnj, 2017-07-08 18:42:44]

dnj@chromium.org changed reviewers:
+ iannucci@chromium.org, vadimsh@chromium.org

[dnj, 2017-07-08 18:42:45]

PTAL. This is blocking LUCI CQ at the moment, b/c of referenced issue.

[commit-bot: I haz the power, 2017-07-08 18:48:23]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-07-08 18:48:25]

Dry run: This issue passed the CQ dry run.

[iannucci, 2017-07-10 18:14:43]

lgtm

[iannucci, 2017-07-10 18:16:13]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2017-07-10 18:16:18]

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, 2017-07-10 18:23:00]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1499710573278130, "parent_rev":
"e39d552a742c975af28cc5a4b99dbabce6a6ef1d", "commit_rev":
"20552da21fbd9b430045c43a86735ff3c8f3cea8"}

[commit-bot: I haz the power, 2017-07-10 18:23:03]

Description was changed from

==========
[grpc/logging] Update to LoggerV2.

The gRPC package has released its "LoggerV2" interface, which tries to
maintain backwards compatibility with Logger but fails (see
https://github.com/grpc/grpc-go/issues/1360).

Update our gRPC logging adapter to operate through LoggerV2.

BUG=None
TEST=unit
==========

to

==========
[grpc/logging] Update to LoggerV2.

The gRPC package has released its "LoggerV2" interface, which tries to
maintain backwards compatibility with Logger but fails (see
https://github.com/grpc/grpc-go/issues/1360).

Update our gRPC logging adapter to operate through LoggerV2.

BUG=None
TEST=unit

Review-Url: https://codereview.chromium.org/2976583002
Committed:
https://github.com/luci/luci-go/commit/20552da21fbd9b430045c43a86735ff3c8f3cea8
==========

[commit-bot: I haz the power, 2017-07-10 18:23:05]

Committed patchset #1 (id:1) as
https://github.com/luci/luci-go/commit/20552da21fbd9b430045c43a86735ff3c8f3cea8