Autofill wallet -- handle several classes of error in unmasking prompt.

Autofill/Wallet -- handle several classes of error in unmasking prompt.

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BUG=463291
Committed: https://crrev.com/fb1d7742a2c6784f50ee723b8c0ce67239fa8173
Cr-Commit-Position: refs/heads/master@{#318821}

[Evan Stade, 2015-03-02 23:41:36]

estade@chromium.org changed reviewers:
+ brettw@chromium.org

[brettw, 2015-03-02 23:54:48]

lgtm

[Evan Stade, 2015-03-03 01:59:21]

The CQ bit was checked by estade@chromium.org

[Evan Stade, 2015-03-03 01:59:21]

The patchset sent to the CQ was uploaded after l-g-t-m from brettw@chromium.org
Link to the patchset: https://codereview.chromium.org/969223002/#ps40001 (title:
"local")

[commit-bot: I haz the power, 2015-03-03 02:00:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/969223002/40001

[commit-bot: I haz the power, 2015-03-03 02:57:30]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-03-03 02:58:03]

Patchset 3 (id:??) landed as
https://crrev.com/fb1d7742a2c6784f50ee723b8c0ce67239fa8173
Cr-Commit-Position: refs/heads/master@{#318821}