Use monotonicallyIncreasingTime for Timeline timestamps

Use monotonicallyIncreasingTime for Timeline timestamps

We used to use pseudo-wall time for Timeline timestamps and had
a hard time converting back-n-forth between monotonicallyIncreasingTime
used by other subsystems and Timeline. This switches Timeline to
monotonicallyIncreasingTime.

BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=170444

[pfeldman, 2014-03-27 13:26:57]

https://codereview.chromium.org/212893002/diff/40001/Source/core/inspector/In...
File Source/core/inspector/InspectorTimelineAgent.cpp (left):

https://codereview.chromium.org/212893002/diff/40001/Source/core/inspector/In...
Source/core/inspector/InspectorTimelineAgent.cpp:261: m_startOffset =
monotonicallyIncreasingTime() - currentTime();
I am not sure what this gives you. Either wall or zero-based time is good since
you can sync events that happen within core, or is that not so?

https://codereview.chromium.org/212893002/diff/40001/Source/core/inspector/In...
File Source/core/inspector/InspectorTimelineAgent.cpp (right):

https://codereview.chromium.org/212893002/diff/40001/Source/core/inspector/In...
Source/core/inspector/InspectorTimelineAgent.cpp:1274: double
InspectorTimelineAgent::toTimelineTimestamp(double monotonicallyIncreasingTime)
There is no "timeline timestamp", it is millis all over.

[caseq, 2014-03-31 07:56:55]

On 2014/03/27 13:26:57, pfeldman wrote:
>
https://codereview.chromium.org/212893002/diff/40001/Source/core/inspector/In...
> File Source/core/inspector/InspectorTimelineAgent.cpp (left):
> 
>
https://codereview.chromium.org/212893002/diff/40001/Source/core/inspector/In...
> Source/core/inspector/InspectorTimelineAgent.cpp:261: m_startOffset =
> monotonicallyIncreasingTime() - currentTime();
> I am not sure what this gives you. Either wall or zero-based time is good
since
> you can sync events that happen within core, or is that not so?

Either is good, but since we receive other signals (e.g. trace) in
monotinicallyIncreasingTime(), we would need to have the offset between that and
the wall or 0-based time. I'm not particularly attached to timeline time being
in monotinicallyIncreasingTime, but this keeps things simpler by eliminating
offsets.

> 
>
https://codereview.chromium.org/212893002/diff/40001/Source/core/inspector/In...
> File Source/core/inspector/InspectorTimelineAgent.cpp (right):
> 
>
https://codereview.chromium.org/212893002/diff/40001/Source/core/inspector/In...
> Source/core/inspector/InspectorTimelineAgent.cpp:1274: double
> InspectorTimelineAgent::toTimelineTimestamp(double
monotonicallyIncreasingTime)
> There is no "timeline timestamp", it is millis all over.

Inlined as x * msPerSecond all over the place as per offline discussion.

[alph, 2014-03-31 08:27:42]

Make sure it won't break any tests. I remember there was one that expected
timestamps be in wall-time.

[pfeldman, 2014-03-31 09:25:51]

lgtm

[caseq, 2014-03-31 09:33:42]

The CQ bit was checked by caseq@chromium.org

[commit-bot: I haz the power, 2014-03-31 09:33:50]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/caseq@chromium.org/212893002/70001

[alph, 2014-03-31 09:42:46]

On 2014/03/31 09:33:50, I haz the power (commit-bot) wrote:
> CQ is trying da patch. Follow status at
> https://chromium-status.appspot.com/cq/caseq@chromium.org/212893002/70001

Hmm, I'm wondering how does inspector/timeline/timeline-start-time.html pass?

[commit-bot: I haz the power, 2014-03-31 09:44:21]

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

[commit-bot: I haz the power, 2014-03-31 09:44:21]

Try jobs failed on following builders:
  tryserver.blink on win_blink_rel

[caseq, 2014-03-31 12:19:55]

The CQ bit was checked by caseq@chromium.org

[commit-bot: I haz the power, 2014-03-31 12:19:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/caseq@chromium.org/212893002/90001

[commit-bot: I haz the power, 2014-03-31 12:53:12]

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

[commit-bot: I haz the power, 2014-03-31 12:53:13]

Try jobs failed on following builders:
  tryserver.blink on win_blink_rel

[caseq, 2014-03-31 13:00:27]

The CQ bit was checked by caseq@chromium.org

[commit-bot: I haz the power, 2014-03-31 13:00:33]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/caseq@chromium.org/212893002/90001

[commit-bot: I haz the power, 2014-03-31 13:49:59]

Change committed as 170444