Instrument EDK sync Broker initialization

Instrument EDK sync Broker initialization

Bringing up Mojo at process startup caused a regression
on OS X renderer startup times. At least half of the
regression seems to be attributable to blocking on
getting the parent pipe handle from the sync broker
channel.

We can eliminate this behavior on OS X now that we're
using Mach shm, but let's also make sure it's not causing
problems elsewhere in the wild.

BUG=591742
Committed: https://crrev.com/c326671407f8790fbb7ee14ca59ac37aa25afa87
Cr-Commit-Position: refs/heads/master@{#381953}

[Ken Rockot(use gerrit already), 2016-03-18 04:54:38]

rockot@chromium.org changed reviewers:
+ amistry@chromium.org, isherman@chromium.org

[Ken Rockot(use gerrit already), 2016-03-18 04:54:39]

PTAL! amistry for mojo, isherman for histograms. Thanks

[Ilya Sherman, 2016-03-18 04:56:22]

metrics lgtm

[Anand Mistry (off Chromium), 2016-03-18 05:35:02]

lgtm

[Ken Rockot(use gerrit already), 2016-03-18 05:57:56]

The CQ bit was checked by rockot@chromium.org

[commit-bot: I haz the power, 2016-03-18 05:58:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1805923006/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1805923006/1

[commit-bot: I haz the power, 2016-03-18 07:05:22]

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

[commit-bot: I haz the power, 2016-03-18 07:05:24]

Try jobs failed on following builders:
  win_chromium_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[Ken Rockot(use gerrit already), 2016-03-18 13:15:09]

The CQ bit was checked by rockot@chromium.org

[commit-bot: I haz the power, 2016-03-18 13:15:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1805923006/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1805923006/1

[commit-bot: I haz the power, 2016-03-18 13:50:45]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-18 13:52:23]

Description was changed from

==========
Instrument EDK sync Broker initialization

Bringing up Mojo at process startup caused a regression
on OS X renderer startup times. At least half of the
regression seems to be attributable to blocking on
getting the parent pipe handle from the sync broker
channel.

We can eliminate this behavior on OS X now that we're
using Mach shm, but let's also make sure it's not causing
problems elsewhere in the wild.

BUG=591742
==========

to

==========
Instrument EDK sync Broker initialization

Bringing up Mojo at process startup caused a regression
on OS X renderer startup times. At least half of the
regression seems to be attributable to blocking on
getting the parent pipe handle from the sync broker
channel.

We can eliminate this behavior on OS X now that we're
using Mach shm, but let's also make sure it's not causing
problems elsewhere in the wild.

BUG=591742

Committed: https://crrev.com/c326671407f8790fbb7ee14ca59ac37aa25afa87
Cr-Commit-Position: refs/heads/master@{#381953}
==========

[commit-bot: I haz the power, 2016-03-18 13:52:25]

Patchset 1 (id:??) landed as
https://crrev.com/c326671407f8790fbb7ee14ca59ac37aa25afa87
Cr-Commit-Position: refs/heads/master@{#381953}