The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/55517958060e2499136ac8112dfed9b653c3f073

commit 55517958060e2499136ac8112dfed9b653c3f073
Author: Megumi Hattori <megumihattori@google.com>
Date: Mon Mar 19 04:37:14 2018

Enable IME on lock screen behind flag, enable-lock-screen-notification.

This CL enables IME on lock screen behind flag,
--enable-lock-screen-notification, in order to enable input of languages
other than English in the inline reply on notifications.

BUG= 823184 
TEST=manual

Change-Id: I820e70855be414756d2d4f0ee9e90ee92edb2c3c
Reviewed-on: https://chromium-review.googlesource.com/966248
Commit-Queue: Megumi Hattori <megumihattori@google.com>
Reviewed-by: Yuichiro Hanada <yhanada@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543968}
[modify] https://crrev.com/55517958060e2499136ac8112dfed9b653c3f073/chrome/browser/chromeos/input_method/input_method_manager_impl.cc