Reland "Don't record first filling result for sign-in forms"

This reverts commit c13cea62d0816ae1ea2c8184e96f77fd459d478e.

Reason for revert: Fixed memory problem

Original change's description:
> Revert "Don't record first filling result for sign-in forms"
>
> This reverts commit 34d69265b1f1f5a3c7739827a0b7e05bfc928e08.
>
> Reason for revert: breaks msan
> https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20MSan%20Tests/14500
>
> Original change's description:
> > Don't record first filling result for sign-in forms
> >
> > The new form parser may decide that a form has no current-password element, but
> > only new-password / confirmation elements. In this case, the parser sets the
> > unique_renderer_id to 'undefined'. The credentials will be sent to the renderer
> > for filling via manual fallback but the renderer won't ever fill (as there is
> > no password element defined for filling.
> >
> > This CL ensures that this case does not get recorded as a failure to fill. This
> > is important because we record two metrics about the first fill attempt:
> > PasswordManager.FirstWaitForUsernameReason and
> > PasswordManager.FirstRendererFillingResult For websites that have a sign-up
> > form followed by a sign-in form, we don't want to record the failure to fill on
> > the sign-up form.
> >
> > Bug: 918846
> > Change-Id: I79e9a73ae3573a81e121eaa483e0ecef0889184f
> > Reviewed-on: https://chromium-review.googlesource.com/c/1422018
> > Commit-Queue: Dominic Battré <battre@chromium.org>
> > Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#625178}
>
> TBR=battre@chromium.org,dvadym@chromium.org
>
> Change-Id: I3c68004b67b5fcc65511c611c2d205297596e782
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 918846
> Reviewed-on: https://chromium-review.googlesource.com/c/1430581
> Reviewed-by: John Abd-El-Malek <jam@chromium.org>
> Commit-Queue: John Abd-El-Malek <jam@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#625227}

TBR=dvadym@chromium.org,jam@chromium.org

Bug: 918846
Change-Id: I671bc4674f1660920eae0c73d5b1b01b49311383
Reviewed-on: https://chromium-review.googlesource.com/c/1431172
Reviewed-by: Dominic Battré <battre@chromium.org>
Commit-Queue: Dominic Battré <battre@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625375}
4 files changed