[Tracing] Fix inaccurate time accumulation in runtime statistics.

[Tracing] Fix inaccurate time accumulation in runtime statistics.

In tracing we collect runtime statistics data based on top level trace events,
in this patch we force to clear the whole runtime statistics stack when we
enter top level trace events.

Committed: https://crrev.com/1f96226bc2d36c5a4f7fec84b7852ef4e06c3c7b
Cr-Commit-Position: refs/heads/master@{#40867}

[lpy, 2016-11-04 23:20:33]

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

[commit-bot: I haz the power, 2016-11-04 23:20:43]

Dry run: 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, 2016-11-04 23:57:54]

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

[commit-bot: I haz the power, 2016-11-04 23:57:54]

Dry run: This issue passed the CQ dry run.

[lpy, 2016-11-08 03:55:17]

lpy@chromium.org changed reviewers:
+ fmeawad@chromium.org

[lpy, 2016-11-08 03:55:18]

ptal

[lpy, 2016-11-08 18:22:11]

Description was changed from

==========
[Tracing] Fix inaccurate time accumulation in runtime statistics.
==========

to

==========
[Tracing] Fix inaccurate time accumulation in runtime statistics.

In tracing we collect runtime statistics data based on top level trace events,
in this patch we force to clear the whole runtime statistics stack when we
enter top level trace events.
==========

[fmeawad, 2016-11-08 23:23:59]

I have tried this CL on the top 25 pages and it seems to fix the issue.

LGTM

[lpy, 2016-11-08 23:54:18]

lpy@chromium.org changed reviewers:
+ cbruni@chromium.org

[lpy, 2016-11-08 23:54:18]

+ cbruni@, ptal.

[Camillo Bruni, 2016-11-09 12:06:22]

lgtm

[lpy, 2016-11-09 16:41:43]

The CQ bit was checked by lpy@chromium.org

[commit-bot: I haz the power, 2016-11-09 16:41:52]

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, 2016-11-09 17:07:58]

Description was changed from

==========
[Tracing] Fix inaccurate time accumulation in runtime statistics.

In tracing we collect runtime statistics data based on top level trace events,
in this patch we force to clear the whole runtime statistics stack when we
enter top level trace events.
==========

to

==========
[Tracing] Fix inaccurate time accumulation in runtime statistics.

In tracing we collect runtime statistics data based on top level trace events,
in this patch we force to clear the whole runtime statistics stack when we
enter top level trace events.
==========

[commit-bot: I haz the power, 2016-11-09 17:07:59]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-17 22:27:50]

Description was changed from

==========
[Tracing] Fix inaccurate time accumulation in runtime statistics.

In tracing we collect runtime statistics data based on top level trace events,
in this patch we force to clear the whole runtime statistics stack when we
enter top level trace events.
==========

to

==========
[Tracing] Fix inaccurate time accumulation in runtime statistics.

In tracing we collect runtime statistics data based on top level trace events,
in this patch we force to clear the whole runtime statistics stack when we
enter top level trace events.

Committed: https://crrev.com/1f96226bc2d36c5a4f7fec84b7852ef4e06c3c7b
Cr-Commit-Position: refs/heads/master@{#40867}
==========

[commit-bot: I haz the power, 2016-11-17 22:27:52]

Patchset 1 (id:??) landed as
https://crrev.com/1f96226bc2d36c5a4f7fec84b7852ef4e06c3c7b
Cr-Commit-Position: refs/heads/master@{#40867}