Credential Manager: Return the first valid item from the PasswordStore.

Credential Manager: Return the first valid item from the PasswordStore.

This patch completes the initial, dead simple, pretty dumb implementation
of '.request()'. We poke at the PasswordStore for the origin currently
committed in the RenderViewHost's main frame, and if we get anything at
all, we return it.

We can't expose this implementation to the web for obvious reasons. But
it's pefectly wonderful for testing.

------------------------------------------------------------------------
This is a re-land of https://codereview.chromium.org/613143003/, which
was reverted due to LSAN issues caused by not properly taking ownership
of PasswordForm objects returned from PasswordStore::GetLogins.
------------------------------------------------------------------------

BUG=400674
R=vabr@chromium.org

Committed: https://crrev.com/124fe9402f30fd855c3673f77af176e3e97b7592
Cr-Commit-Position: refs/heads/master@{#297619}

[Mike West, 2014-10-01 07:40:09]

vabr@ can you take a quick look at this? The only difference from the patch
which was reverted (and which you approved yesterday) is the addition of a
ScopedVector on line 98 of
https://codereview.chromium.org/615383002/diff/1/components/password_manager/....

-mike

[vabr (Chromium), 2014-10-01 09:52:22]

On 2014/10/01 07:40:09, Mike West wrote:
> vabr@ can you take a quick look at this? The only difference from the patch
> which was reverted (and which you approved yesterday) is the addition of a
> ScopedVector on line 98 of
>
https://codereview.chromium.org/615383002/diff/1/components/password_manager/....
> 
> -mike

LGTM, Thanks for the quick fix.

Also sorry for missing this in the review. It's amazing, that the automated
sanitisers can find this out immediately, though! :)

Vaclav

[Mike West, 2014-10-01 09:54:01]

The CQ bit was checked by mkwst@chromium.org

[commit-bot: I haz the power, 2014-10-01 09:54:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/615383002/1

[commit-bot: I haz the power, 2014-10-01 09:58:40]

Committed patchset #1 (id:1) as 2020c1c53cbdd58cfc87db8addc45f1ed1d6cdae

[commit-bot: I haz the power, 2014-10-01 09:59:16]

Patchset 1 (id:??) landed as
https://crrev.com/124fe9402f30fd855c3673f77af176e3e97b7592
Cr-Commit-Position: refs/heads/master@{#297619}