[ios] Add flag for iOS password generation

Bug: 886583
Change-Id: I107a11cdcd9d299533789cffed8c3446561f4968
Reviewed-on: https://chromium-review.googlesource.com/c/1365432
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Commit-Queue: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615464}
12 files changed