UMA for data reduction proxy probe net errors

UMA for data reduction proxy probe net errors

Added UMA to report the type of net error that occurred
when the data reduction proxy probe failed due to a
network error. Note the probe can also fail due to
the response being modified, which this UMA does not
track.

BUG=397256
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=285711

[bengr, 2014-07-25 17:57:18]

mmenke: data_reduction_proxy_settings.cc
asvitkine: histograms.xml

[Alexei Svitkine (slow), 2014-07-25 18:03:31]

lgtm

[mmenke, 2014-07-25 18:27:00]

LGTM, with this change.

https://codereview.chromium.org/417253002/diff/1/components/data_reduction_pr...
File components/data_reduction_proxy/browser/data_reduction_proxy_settings.cc
(right):

https://codereview.chromium.org/417253002/diff/1/components/data_reduction_pr...
components/data_reduction_proxy/browser/data_reduction_proxy_settings.cc:250:
kUMAProxyProbeURLNetError, std::abs(status.error()));
    UMA_HISTOGRAM_CUSTOM_ENUMERATION(kUMAProxyProbeURLNetError,
                                     std::abs(status.error()),
                                     net::GetAllErrorCodesForUma());

[Alexei Svitkine (slow), 2014-07-25 18:28:21]

https://codereview.chromium.org/417253002/diff/1/components/data_reduction_pr...
File components/data_reduction_proxy/browser/data_reduction_proxy_settings.cc
(right):

https://codereview.chromium.org/417253002/diff/1/components/data_reduction_pr...
components/data_reduction_proxy/browser/data_reduction_proxy_settings.cc:250:
kUMAProxyProbeURLNetError, std::abs(status.error()));
On 2014/07/25 18:27:00, mmenke wrote:
>     UMA_HISTOGRAM_CUSTOM_ENUMERATION(kUMAProxyProbeURLNetError,
>                                      std::abs(status.error()),
>                                      net::GetAllErrorCodesForUma());

No, sparse histogram is better in this case, as it avoids allocating a giant
array for all the possible net buckets.

[mmenke, 2014-07-25 18:28:50]

On 2014/07/25 18:28:21, Alexei Svitkine wrote:
>
https://codereview.chromium.org/417253002/diff/1/components/data_reduction_pr...
> File components/data_reduction_proxy/browser/data_reduction_proxy_settings.cc
> (right):
> 
>
https://codereview.chromium.org/417253002/diff/1/components/data_reduction_pr...
> components/data_reduction_proxy/browser/data_reduction_proxy_settings.cc:250:
> kUMAProxyProbeURLNetError, std::abs(status.error()));
> On 2014/07/25 18:27:00, mmenke wrote:
> >     UMA_HISTOGRAM_CUSTOM_ENUMERATION(kUMAProxyProbeURLNetError,
> >                                      std::abs(status.error()),
> >                                      net::GetAllErrorCodesForUma());
> 
> No, sparse histogram is better in this case, as it avoids allocating a giant
> array for all the possible net buckets.

Ok, LGTM as-is, then.

[bengr, 2014-07-25 19:03:26]

The CQ bit was checked by bengr@chromium.org

[commit-bot: I haz the power, 2014-07-25 19:05:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/bengr@chromium.org/417253002/1

[commit-bot: I haz the power, 2014-07-25 22:26:17]

Change committed as 285711