Additional tracing and histogram in Extensions startup.

Additional tracing and histogram in Extensions startup.

Followed a local Linux machine which was slower than expected to where the time was going. Stopped at the ExtensionManagement::Refresh level, and will measure if this is general slow.

BUG=454789
Committed: https://crrev.com/dd66a1342eeffa5d2cca8e1b3b35c86001094dfe
Cr-Commit-Position: refs/heads/master@{#319173}

[rkaplow, 2015-03-03 20:37:18]

rkaplow@chromium.org changed reviewers:
+ asvitkine@chromium.org, caitkp@chromium.org, yoz@chromium.org

[rkaplow, 2015-03-03 20:37:57]

Please review

caitkp:
  keyed_service
yoz/asvitkine:
  everything else

[Alexei Svitkine (slow), 2015-03-03 23:03:35]

lgtm

[Yoyo Zhou, 2015-03-04 00:35:32]

LGTM

[rkaplow, 2015-03-04 15:07:28]

rkaplow@chromium.org changed reviewers:
+ erg@chromium.org
- caitkp@chromium.org

[rkaplow, 2015-03-04 15:08:04]

rkaplow@chromium.org changed reviewers:
+ caitkp@chromium.org

[rkaplow, 2015-03-04 15:08:05]

adding erg@ for keyed_service

[Elliot Glaysher, 2015-03-04 19:06:00]

lgtm conditional on if you are ok with this:

https://codereview.chromium.org/977673002/diff/1/components/keyed_service/cor...
File components/keyed_service/core/keyed_service_factory.cc (right):

https://codereview.chromium.org/977673002/diff/1/components/keyed_service/cor...
components/keyed_service/core/keyed_service_factory.cc:62:
TRACE_EVENT0("browser,startup", "KeyedServiceFactory::GetServiceForContext");
I expect that this event will be extremely spammy. All access to all components
come through this method.

[rkaplow, 2015-03-04 23:26:48]

On 2015/03/04 19:06:00, Elliot Glaysher wrote:
> lgtm conditional on if you are ok with this:
> 
>
https://codereview.chromium.org/977673002/diff/1/components/keyed_service/cor...
> File components/keyed_service/core/keyed_service_factory.cc (right):
> 
>
https://codereview.chromium.org/977673002/diff/1/components/keyed_service/cor...
> components/keyed_service/core/keyed_service_factory.cc:62:
> TRACE_EVENT0("browser,startup", "KeyedServiceFactory::GetServiceForContext");
> I expect that this event will be extremely spammy. All access to all
components
> come through this method.

I'm looking at some sample traces, and I think this is considered ok. There's
lot of other trace events which are just as spammy, such as View::Paint or
DirectRenderer::DrawFrame.

If someone wants to get rid of all spammy traces that is fine, but this is still
a bit useful to see.

[rkaplow, 2015-03-04 23:27:01]

The CQ bit was checked by rkaplow@chromium.org

[commit-bot: I haz the power, 2015-03-04 23:28:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/977673002/1

[commit-bot: I haz the power, 2015-03-05 00:32:01]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-05 00:32:40]

Patchset 1 (id:??) landed as
https://crrev.com/dd66a1342eeffa5d2cca8e1b3b35c86001094dfe
Cr-Commit-Position: refs/heads/master@{#319173}