Teach form_parser use server hints

This CL extends the browser-side FormData parser in password manager to
use server predictions to determine roles of input fields.

This support is incomplete and does not handle well partial predictions
yet, e.g., if only the USERNAME is predicted. It also does not handle
the "NOT_PASSWORD" prediction. Those will get addressed in separate CLs.

Bug: 845426
Change-Id: If8e444fb865c2c8358b122fed875386a9aa05ec8
Reviewed-on: https://chromium-review.googlesource.com/1087066
Commit-Queue: Vaclav Brozek <[email protected]>
Reviewed-by: Vadym Doroshenko <[email protected]>
Cr-Commit-Position: refs/heads/master@{#566388}
5 files changed