[Content suggestions] Report updates in the UI to UMA - cleanup

[Content suggestions] Report updates in the UI to UMA - cleanup

A cleanup of after-lgtm changes from CL 2639533003. This CL separates
the enum histogram from a counter. They were previously mixed together
in one CL.

BUG=674163
Review-Url: https://codereview.chromium.org/2643293003
Cr-Commit-Position: refs/heads/master@{#445287}
Committed: https://chromium.googlesource.com/chromium/src/+/858ceafc7cf4f11a6549b8c1ace839a45d943d68

[jkrcal, 2017-01-20 18:05:52]

jkrcal@chromium.org changed reviewers:
+ dgn@chromium.org, rkaplow@chromium.org

[jkrcal, 2017-01-20 18:05:52]

Nicolas, Robert, PTAL!

(This Cl responds to comments of Nicolas to my after-lgtm changes to
https://codereview.chromium.org/2639533003/. Sorry for the mess.)

[jkrcal, 2017-01-20 18:09:17]

https://codereview.chromium.org/2643293003/diff/40001/tools/metrics/histogram...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/2643293003/diff/40001/tools/metrics/histogram...
tools/metrics/histograms/histograms.xml:39367: +  <obsolete>
Robert, could we actually do it without renaming and obsoleting the previous
histogram (given it is not even one day old)? Actually, the question has two
levels:
 - is changing a very fresh histogram generally possible?
 - if so, is it possible when there was a branch point, in between? ;)

[jkrcal, 2017-01-20 18:09:25]

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

[commit-bot: I haz the power, 2017-01-20 18:09:42]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[rkaplow, 2017-01-20 18:54:50]

On 2017/01/20 18:09:17, jkrcal wrote:
>
https://codereview.chromium.org/2643293003/diff/40001/tools/metrics/histogram...
> File tools/metrics/histograms/histograms.xml (right):
> 
>
https://codereview.chromium.org/2643293003/diff/40001/tools/metrics/histogram...
> tools/metrics/histograms/histograms.xml:39367: +  <obsolete>
> Robert, could we actually do it without renaming and obsoleting the previous
> histogram (given it is not even one day old)? Actually, the question has two
> levels:
>  - is changing a very fresh histogram generally possible?
>  - if so, is it possible when there was a branch point, in between? ;)

We don't recommend it but it is possible. If it only exists for a very small
amount of time you will only get a small amount of noisy/incorrect data. So if
the only release in between were to be a canary I'd say it's fine. However if it
missed a branch point you're going to get bad data for a long time - so best to
just make a new histogram.

[rkaplow, 2017-01-20 18:55:30]

lgtm

[commit-bot: I haz the power, 2017-01-20 19:09:53]

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

[commit-bot: I haz the power, 2017-01-20 19:09:54]

Dry run: This issue passed the CQ dry run.

[dgn, 2017-01-20 19:52:06]

lgtm

[jkrcal, 2017-01-21 11:22:29]

The CQ bit was checked by jkrcal@chromium.org

[commit-bot: I haz the power, 2017-01-21 11:22:36]

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, 2017-01-21 11:26:02]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1484997749009520,
"parent_rev": "22e6e7a5ceb5a0ab6e207184032ef6026fde5611", "commit_rev":
"858ceafc7cf4f11a6549b8c1ace839a45d943d68"}

[commit-bot: I haz the power, 2017-01-21 11:26:33]

Description was changed from

==========
[Content suggestions] Report updates in the UI to UMA - cleanup

A cleanup of after-lgtm changes from CL 2639533003. This CL separates
the enum histogram from a counter. They were previously mixed together
in one CL.

BUG=674163
==========

to

==========
[Content suggestions] Report updates in the UI to UMA - cleanup

A cleanup of after-lgtm changes from CL 2639533003. This CL separates
the enum histogram from a counter. They were previously mixed together
in one CL.

BUG=674163

Review-Url: https://codereview.chromium.org/2643293003
Cr-Commit-Position: refs/heads/master@{#445287}
Committed:
https://chromium.googlesource.com/chromium/src/+/858ceafc7cf4f11a6549b8c1ace8...
==========

[commit-bot: I haz the power, 2017-01-21 11:26:34]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/858ceafc7cf4f11a6549b8c1ace8...