Extend autofill controller delegate for password autofilling logic in //ios/web_view.

Bug: 865114
Cq-Include-Trybots: luci.chromium.try:ios-simulator-cronet;luci.chromium.try:ios-simulator-full-configs
Change-Id: I48e317b989129cf391ece111df72f98eb62504d1
Reviewed-on: https://chromium-review.googlesource.com/c/1226950
Commit-Queue: Scott Wu <scottwu@chromium.org>
Reviewed-by: Hiroshi Ichikawa <ichikawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596478}
14 files changed