Revert of [Password Manager] Send username correction votes

Revert of [Password Manager] Send username correction votes (patchset #20 id:440001 of https://codereview.chromium.org/2747733004/ )

Reason for revert:
Suspect that this is causing browser_tests and interactive_ui_tests failures

Original issue's description:
> [Password Manager] Send username correction votes
> 
> If a user changes autofilled username on a form, but the correct username is in |PasswordForm.other_possible_usernames|, send USERNAME vote for the element that contained the correct username. 
> 
> This CL changes the data structure of |other_possible_usernames| from vector<string> to vector<pair<string, string>>. 
> 
> The CL updates only one local storage - login_database. We need to receive enough votes, there is no need to cover 100% of Chrome instances. But the results based on the votes would propagated to all instances.
> 
> BUG=699530
> 
> Review-Url: https://codereview.chromium.org/2747733004
> Cr-Commit-Position: refs/heads/master@{#458788}
> Committed: https://chromium.googlesource.com/chromium/src/+/718d242b21b1964f8a06e79bf00dcce7e073dac7

TBR=mkwst@chromium.org,dvadym@chromium.org,vabr@chromium.org,kolos@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=699530

[adithyas, 2017-07-31 21:15:51]

The CQ bit was checked by adithyas@chromium.org

[adithyas, 2017-07-31 21:15:52]

Created Revert of [Password Manager] Send username correction votes

[commit-bot: I haz the power, 2017-07-31 21:16:04]

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, 2017-07-31 21:20:38]

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

[commit-bot: I haz the power, 2017-07-31 21:20:39]

Try jobs failed on following builders:
  android_cronet on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_cron...)
  linux_android_rel_ng on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_androi...)

[kolos1, 2017-08-01 08:58:23]

Hi Adithya!

In revert reason, please give more info about test failures. Interactive test is
very flaky, so please double check that you revert the right CL.

This CL doesn't change any UI behavior. It hardly affect on interactive tests.

All the best,
Maxim

[adithyas, 2017-08-01 12:50:25]

On 2017/08/01 at 08:58:23, kolos wrote:
> Hi Adithya!
> 
> In revert reason, please give more info about test failures. Interactive test
is very flaky, so please double check that you revert the right CL.
> 
> This CL doesn't change any UI behavior. It hardly affect on interactive tests.
> 
> All the best,
> Maxim

Hey! Sorry about that, I realized this CL couldn't have caused the failures so I
just closed the issue after the try bots failed.