[Password Manager] Add UMA statistics for PasswordForm::ssl_valid usage

[Password Manager] Add UMA statistics for PasswordForm::ssl_valid usage

We are planning to drop the PasswordForm::ssl_valid field as it's no longer used in new password forms and we believe it was set very rarely. This change will give us the statistics to confirm our belief.

BUG=413020
Committed: https://crrev.com/6cfdae92467fe89ffa4ac5d5d65046757ac516b9
Cr-Commit-Position: refs/heads/master@{#338103}

[xunlu, 2015-07-07 00:33:03]

Patchset #1 (id:1) has been deleted

[xunlu, 2015-07-07 00:40:41]

xunlu@chromium.org changed reviewers:
+ gcasto@chromium.org

[Garrett Casto, 2015-07-07 22:35:18]

https://codereview.chromium.org/1217273007/diff/20001/components/password_man...
File components/password_manager/core/browser/login_database.cc (right):

https://codereview.chromium.org/1217273007/diff/20001/components/password_man...
components/password_manager/core/browser/login_database.cc:544:
invalid_ssl_cert_statement.ColumnInt(1) > 0);
Isn't this backwards? That is when ssl_valid is true, the histogram, which
sounds like it counts the number of invalid certs, is true.

https://codereview.chromium.org/1217273007/diff/20001/tools/metrics/histogram...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1217273007/diff/20001/tools/metrics/histogram...
tools/metrics/histograms/histograms.xml:28047: +    Whether a password form
stored by user for an HTTPS enabled website had
Nit: I would probably phrase this something like "Whether saved password for
HTTPS sites had a valid SSL cert when the password was saved." Specifically I
think that it's useful to explain what |ssl_valid| actually means.

[xunlu, 2015-07-08 00:02:52]

https://codereview.chromium.org/1217273007/diff/20001/components/password_man...
File components/password_manager/core/browser/login_database.cc (right):

https://codereview.chromium.org/1217273007/diff/20001/components/password_man...
components/password_manager/core/browser/login_database.cc:544:
invalid_ssl_cert_statement.ColumnInt(1) > 0);
On 2015/07/07 22:35:18, Garrett Casto wrote:
> Isn't this backwards? That is when ssl_valid is true, the histogram, which
> sounds like it counts the number of invalid certs, is true.

Oops. 
Done

https://codereview.chromium.org/1217273007/diff/20001/tools/metrics/histogram...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1217273007/diff/20001/tools/metrics/histogram...
tools/metrics/histograms/histograms.xml:28047: +    Whether a password form
stored by user for an HTTPS enabled website had
On 2015/07/07 22:35:18, Garrett Casto wrote:
> Nit: I would probably phrase this something like "Whether saved password for
> HTTPS sites had a valid SSL cert when the password was saved." Specifically I
> think that it's useful to explain what |ssl_valid| actually means.

Done.

[Garrett Casto, 2015-07-08 00:33:30]

lgtm

[xunlu, 2015-07-08 17:15:12]

xunlu@chromium.org changed reviewers:
+ jwd@chromium.org

[xunlu, 2015-07-08 17:15:13]

@jwd: please take a look at the histograms.xml change

[jwd, 2015-07-09 14:37:10]

lgtm

[xunlu, 2015-07-09 17:33:17]

The CQ bit was checked by xunlu@chromium.org

[commit-bot: I haz the power, 2015-07-09 17:34:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1217273007/40001

[commit-bot: I haz the power, 2015-07-09 18:55:53]

Committed patchset #2 (id:40001)

[commit-bot: I haz the power, 2015-07-09 18:57:01]

Patchset 2 (id:??) landed as
https://crrev.com/6cfdae92467fe89ffa4ac5d5d65046757ac516b9
Cr-Commit-Position: refs/heads/master@{#338103}