Remove '--arc-input-method' flag.

It's enabled by default now.

Bug: 924383
Test: unit_tests --gtest_filter=ArcInputMethod*
Change-Id: Idaa38371fede902b1779f2482442388dece4721b
Reviewed-on: https://chromium-review.googlesource.com/c/1429322
Reviewed-by: Yusuke Sato <yusukes@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Auto-Submit: Yuichiro Hanada <yhanada@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625198}
9 files changed