Avoid construction of unused RtcEventLogNullImpl object

Avoid construction of unused RtcEventLogNullImpl object

This CL addresses to nits:
1. When event_log_factory_ is not null, there's no need to create a RtcEventLogNullImpl object.
2. Use MakeUnique.

BUG=None

Review-Url: https://codereview.webrtc.org/3012763002
Cr-Commit-Position: refs/heads/master@{#19686}
Committed: https://chromium.googlesource.com/external/webrtc/+/393a9f6926636b94ec8accd5dfe4cd6e5c8ebafe

[eladalon, 2017-09-05 10:56:36]

eladalon@webrtc.org changed reviewers:
+ stefan@webrtc.org, terelius@webrtc.org

[eladalon, 2017-09-05 10:56:37]

PTAL

[stefan-webrtc, 2017-09-05 10:58:38]

lgtm

[terelius, 2017-09-05 10:58:56]

lgtm

[eladalon, 2017-09-05 11:04:48]

The CQ bit was checked by eladalon@webrtc.org

[commit-bot: I haz the power, 2017-09-05 11:04:59]

CQ is trying da patch.

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

[commit-bot: I haz the power, 2017-09-05 11:30:31]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1504609488182180, "parent_rev":
"7eb938d4c065014a6d33a4258b6e85e28de28359", "commit_rev":
"393a9f6926636b94ec8accd5dfe4cd6e5c8ebafe"}

[commit-bot: I haz the power, 2017-09-05 11:30:36]

Description was changed from

==========
Avoid construction of unused RtcEventLogNullImpl object

This CL addresses to nits:
1. When event_log_factory_ is not null, there's no need to create a
RtcEventLogNullImpl object.
2. Use MakeUnique.

BUG=None
==========

to

==========
Avoid construction of unused RtcEventLogNullImpl object

This CL addresses to nits:
1. When event_log_factory_ is not null, there's no need to create a
RtcEventLogNullImpl object.
2. Use MakeUnique.

BUG=None

Review-Url: https://codereview.webrtc.org/3012763002
Cr-Commit-Position: refs/heads/master@{#19686}
Committed:
https://chromium.googlesource.com/external/webrtc/+/393a9f6926636b94ec8accd5d...
==========

[commit-bot: I haz the power, 2017-09-05 11:30:38]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/393a9f6926636b94ec8accd5d...