LatencyInfo: enable async event reporting for both latencyInfo and benchmark categories

LatencyInfo: enable async event reporting for both latencyInfo and benchmark categories

This fixes initializer for benchmark_enabled to actually check for both benchmark and
latencyInfo to match the categories actually used in trace events and renames it to
latency_info_enabled.

BUG=520659
Committed: https://crrev.com/56c76b9d223dd91d7176ec5b9613e3c66321d0de
Cr-Commit-Position: refs/heads/master@{#361172}

[caseq, 2015-11-19 20:29:59]

caseq@chromium.org changed reviewers:
+ jbauman@chromium.org, tdresser@chromium.org

[tdresser, 2015-11-23 18:40:34]

LGTM

[caseq, 2015-11-23 19:02:22]

The CQ bit was checked by caseq@chromium.org

[commit-bot: I haz the power, 2015-11-23 19:07:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1462923003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1462923003/20001

[commit-bot: I haz the power, 2015-11-23 20:24:49]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-11-23 20:25:52]

Patchset 2 (id:??) landed as
https://crrev.com/56c76b9d223dd91d7176ec5b9613e3c66321d0de
Cr-Commit-Position: refs/heads/master@{#361172}