The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c4b94296bb5c2a17d8d61336c81814b36d1850e7

commit c4b94296bb5c2a17d8d61336c81814b36d1850e7
Author: Xiyuan Xia <xiyuan@chromium.org>
Date: Fri Jun 22 21:31:55 2018

ws2: Wireup SetWindowTextInputState and SetImeVisibility

Text input state and IME visibility are indended for PlatformWindow.
WindowTree calls WindowServiceDelegate to update them.
WindowServiceDelegateImpl forwards the states to
AshWindowTreeHostPlatfom to update the underlying PlatformWindow
if the change comes from an active window.

Bug:  852440 
Change-Id: Id584ba0f5a17768fddd3d54caa2e9da051b14ee7
Reviewed-on: https://chromium-review.googlesource.com/1112069
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569788}
[modify] https://crrev.com/c4b94296bb5c2a17d8d61336c81814b36d1850e7/ash/DEPS
[modify] https://crrev.com/c4b94296bb5c2a17d8d61336c81814b36d1850e7/ash/host/ash_window_tree_host.h
[modify] https://crrev.com/c4b94296bb5c2a17d8d61336c81814b36d1850e7/ash/host/ash_window_tree_host_platform.cc
[modify] https://crrev.com/c4b94296bb5c2a17d8d61336c81814b36d1850e7/ash/host/ash_window_tree_host_platform.h
[modify] https://crrev.com/c4b94296bb5c2a17d8d61336c81814b36d1850e7/ash/ws/window_service_delegate_impl.cc
[modify] https://crrev.com/c4b94296bb5c2a17d8d61336c81814b36d1850e7/ash/ws/window_service_delegate_impl.h
[modify] https://crrev.com/c4b94296bb5c2a17d8d61336c81814b36d1850e7/services/ui/ws2/window_service_delegate.h
[modify] https://crrev.com/c4b94296bb5c2a17d8d61336c81814b36d1850e7/services/ui/ws2/window_tree.cc