QUIC - added a histogram to measure the impact of reading QUIC server

QUIC - added a histogram to measure the impact of reading QUIC server
information from disk cache on 0-RTT.

R=jar@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=256281

[wtc, 2014-03-10 22:18:52]

Patch set 2 LGTM.

https://codereview.chromium.org/193253002/diff/10002/tools/metrics/histograms...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/193253002/diff/10002/tools/metrics/histograms...
tools/metrics/histograms/histograms.xml:10323: +<histogram
name="Net.QuicServerInfo.DiskCacheReadTime" units="milliseconds">

I agree milliseconds is the right time unit for this histogram.

It seems that base::TimeDelta is in microseconds. I assume the histogram code
will convert microseconds to milliseconds for us?

[ramant (doing other things), 2014-03-10 22:26:16]

https://codereview.chromium.org/193253002/diff/10002/tools/metrics/histograms...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/193253002/diff/10002/tools/metrics/histograms...
tools/metrics/histograms/histograms.xml:10323: +<histogram
name="Net.QuicServerInfo.DiskCacheReadTime" units="milliseconds">
On 2014/03/10 22:18:52, wtc wrote:
> 
> I agree milliseconds is the right time unit for this histogram.
> 
> It seems that base::TimeDelta is in microseconds. I assume the histogram code
> will convert microseconds to milliseconds for us?

You are right.

https://code.google.com/p/chromium/codesearch#chromium/src/base/metrics/histo...


calls AddTime and AddTime converts the TimeDelta to milliseconds.


https://code.google.com/p/chromium/codesearch#chromium/src/base/metrics/stats...

[Ryan Hamilton, 2014-03-10 22:28:22]

lgtm

[jar (doing other things), 2014-03-10 22:58:13]

lgtm

[wtc, 2014-03-10 23:08:30]

https://codereview.chromium.org/193253002/diff/10002/tools/metrics/histograms...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/193253002/diff/10002/tools/metrics/histograms...
tools/metrics/histograms/histograms.xml:10323: +<histogram
name="Net.QuicServerInfo.DiskCacheReadTime" units="milliseconds">

On 2014/03/10 22:26:16, ramant wrote:
>
> calls AddTime and AddTime converts the TimeDelta to milliseconds.
>  
>
https://code.google.com/p/chromium/codesearch#chromium/src/base/metrics/stats...

Thanks, Raman. You pointed to the AddTime method of StatsCounter. But
HistogramBase::AddTime does the same conversion:

void HistogramBase::AddTime(const TimeDelta& time) {
  Add(static_cast<Sample>(time.InMilliseconds()));
}

[commit-bot: I haz the power, 2014-03-10 23:11:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rtenneti@chromium.org/193253002/10002

[commit-bot: I haz the power, 2014-03-11 00:04:33]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rtenneti@chromium.org/193253002/10002

[commit-bot: I haz the power, 2014-03-11 07:02:40]

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

[commit-bot: I haz the power, 2014-03-11 07:02:41]

Retried try job too often on win_rel for step(s) base_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[ramant (doing other things), 2014-03-11 17:06:15]

The CQ bit was checked by rtenneti@chromium.org

[commit-bot: I haz the power, 2014-03-11 17:10:19]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rtenneti@chromium.org/193253002/10002

[commit-bot: I haz the power, 2014-03-11 18:47:33]

Change committed as 256281