[Signin] Force using XMLHttpRequest for Multilogin even after io11.

Set listAccounts result stale to true on Multilogin finished.

iOS fully working.

Cq-Include-Trybots: luci.chromium.try:ios-simulator-cronet;luci.chromium.try:ios-simulator-full-configs
Change-Id: Id24213b3c2ab8000bbcc6170140de50bcd84986c
Reviewed-on: https://chromium-review.googlesource.com/1245707
Commit-Queue: Valeriya Sinevich <valeriyas@google.com>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#595119}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 10a6514654945e021b472ac203fd8623be7e8331
2 files changed