Record if the smart bubble suppresses credentials.

In PasswordManager.FillingAssistance we record whether the user was
supported at logging into a site. One case is that this is not happening
because the user has no saved credentials. This CL introduces an enum to
indicate that there are no saved credentials and the user does not get offered
to save them anymore.

(cherry picked from commit 7cd82db22d43e7abd815b93eea13aae7dfa47fb4)

Bug: 918846
Change-Id: I2a041649e629ea38f859a4d88204db6b8fddfb2c
Reviewed-on: https://chromium-review.googlesource.com/c/1448164
Commit-Queue: Dominic Battré <battre@chromium.org>
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#627969}
Reviewed-on: https://chromium-review.googlesource.com/c/1451936
Reviewed-by: Dominic Battré <battre@chromium.org>
Cr-Commit-Position: refs/branch-heads/3683@{#156}
Cr-Branched-From: e51029943e0a38dd794b73caaf6373d5496ae783-refs/heads/master@{#625896}
7 files changed