Add password autofill client and factory classes to ios web view.

Note:
This CL is almost a clone of https://chromium-review.googlesource.com/c/chromium/src/+/1060634
by removing cwv_password_controller and fixing conflicts.

Bug:865114

Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I318fba363d7f6edd8d7b187b29d7e500955f498e
Reviewed-on: https://chromium-review.googlesource.com/1149778
Commit-Queue: Scott Wu <scottwu@chromium.org>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: John Wu <jzw@chromium.org>
Reviewed-by: Hiroshi Ichikawa <ichikawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580481}
14 files changed