[ios] UMA metric to report cache miss for WKWebView cert verification.

[ios] UMA metric to report cache hit/miss for WKWebView cert verification.

WKWebView Web Controller has a cache of pending cert verification
results to avoid extra verifications when presenting SSL interstitial.
This metric helps to understand whether or not cache miss is possible.

BUG=541736
Committed: https://crrev.com/018d0db613993f7ec1b08eb0c7543e0111e242ed
Cr-Commit-Position: refs/heads/master@{#358240}

[Eugene But (OOO till 7-30), 2015-11-04 21:56:18]

Description was changed from

==========
[ios] UMA metric to report cache miss for WKWebView cert verification.

BUG=
==========

to

==========
[ios] UMA metric to report cache miss for WKWebView cert verification.

WKWebView Web Controller has a cache of pending cert verification
results to avoid extra verifications when presenting SSL interstitial.
This metric helps to understand whether or not cache miss is possible.

BUG=541736
==========

[Eugene But (OOO till 7-30), 2015-11-04 21:57:02]

Description was changed from

==========
[ios] UMA metric to report cache miss for WKWebView cert verification.

WKWebView Web Controller has a cache of pending cert verification
results to avoid extra verifications when presenting SSL interstitial.
This metric helps to understand whether or not cache miss is possible.

BUG=541736
==========

to

==========
[ios] UMA metric to report cache hit/miss for WKWebView cert verification.

WKWebView Web Controller has a cache of pending cert verification
results to avoid extra verifications when presenting SSL interstitial.
This metric helps to understand whether or not cache miss is possible.

BUG=541736
==========

[Eugene But (OOO till 7-30), 2015-11-04 21:57:20]

eugenebut@chromium.org changed reviewers:
+ stuartmorgan@chromium.org

[stuartmorgan, 2015-11-05 19:32:56]

lgtm

[Eugene But (OOO till 7-30), 2015-11-05 21:22:05]

eugenebut@chromium.org changed reviewers:
+ isherman@chromium.org

[Eugene But (OOO till 7-30), 2015-11-05 21:22:05]

+isherman for histograms.xml

[Ilya Sherman, 2015-11-05 21:31:14]

https://codereview.chromium.org/1414793014/diff/20001/tools/metrics/histogram...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1414793014/diff/20001/tools/metrics/histogram...
tools/metrics/histograms/histograms.xml:50615: +    enum="BooleanSuccess">
Please define an enum with custom labels for this histogram.

[Eugene But (OOO till 7-30), 2015-11-05 21:35:07]

https://codereview.chromium.org/1414793014/diff/20001/tools/metrics/histogram...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1414793014/diff/20001/tools/metrics/histogram...
tools/metrics/histograms/histograms.xml:50615: +    enum="BooleanSuccess">
On 2015/11/05 21:31:13, Ilya Sherman wrote:
> Please define an enum with custom labels for this histogram.
What is the advantage of a custom enum? "BooleanSuccess" is used by many
diagrams and seems to be suitable for this one.

[Ilya Sherman, 2015-11-05 21:42:01]

https://codereview.chromium.org/1414793014/diff/20001/tools/metrics/histogram...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1414793014/diff/20001/tools/metrics/histogram...
tools/metrics/histograms/histograms.xml:50615: +    enum="BooleanSuccess">
On 2015/11/05 21:35:07, eugenebut wrote:
> On 2015/11/05 21:31:13, Ilya Sherman wrote:
> > Please define an enum with custom labels for this histogram.
> What is the advantage of a custom enum? "BooleanSuccess" is used by many
> diagrams and seems to be suitable for this one.

"Hit" vs. "Miss" is much clearer than "Success" vs "Failure" for a histogram
measuring cache hits.  Note that this is purely a histograms.xml metadata
change; no C++/Obj-C changes needed.

[Eugene But (OOO till 7-30), 2015-11-05 21:55:31]

Thanks! PTAL.

https://codereview.chromium.org/1414793014/diff/20001/tools/metrics/histogram...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1414793014/diff/20001/tools/metrics/histogram...
tools/metrics/histograms/histograms.xml:50615: +    enum="BooleanSuccess">
On 2015/11/05 21:42:01, Ilya Sherman wrote:
> On 2015/11/05 21:35:07, eugenebut wrote:
> > On 2015/11/05 21:31:13, Ilya Sherman wrote:
> > > Please define an enum with custom labels for this histogram.
> > What is the advantage of a custom enum? "BooleanSuccess" is used by many
> > diagrams and seems to be suitable for this one.
> 
> "Hit" vs. "Miss" is much clearer than "Success" vs "Failure" for a histogram
> measuring cache hits.  Note that this is purely a histograms.xml metadata
> change; no C++/Obj-C changes needed.
Sure. Done.

[Ilya Sherman, 2015-11-05 23:06:51]

LGTM

[Eugene But (OOO till 7-30), 2015-11-05 23:15:20]

The CQ bit was checked by eugenebut@chromium.org

[Eugene But (OOO till 7-30), 2015-11-05 23:15:21]

The patchset sent to the CQ was uploaded after l-g-t-m from
stuartmorgan@chromium.org
Link to the patchset: https://codereview.chromium.org/1414793014/#ps40001
(title: "Addressed Ilya's review comments")

[commit-bot: I haz the power, 2015-11-05 23:16:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1414793014/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1414793014/40001

[commit-bot: I haz the power, 2015-11-06 00:36:57]

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

[commit-bot: I haz the power, 2015-11-06 00:36:58]

Try jobs failed on following builders:
  linux_chromium_asan_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Eugene But (OOO till 7-30), 2015-11-06 01:36:04]

The CQ bit was checked by eugenebut@chromium.org

[commit-bot: I haz the power, 2015-11-06 01:37:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1414793014/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1414793014/40001

[commit-bot: I haz the power, 2015-11-06 02:50:42]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-11-06 02:51:37]

Patchset 3 (id:??) landed as
https://crrev.com/018d0db613993f7ec1b08eb0c7543e0111e242ed
Cr-Commit-Position: refs/heads/master@{#358240}