Add keithlee to OWNERS

Change-Id: Ie48fac3c75f6825eca8372abe09afa2696586333
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1816340
Commit-Queue: Keith Lee <keithlee@chromium.org>
Reviewed-by: Ben Wells <benwells@chromium.org>
Reviewed-by: Shu Chen <shuchen@chromium.org>
Reviewed-by: Keith Lee <keithlee@chromium.org>
Auto-Submit: Keith Lee <keithlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699659}

chrome/browser/chromeos/extensions/OWNERS

@@ -10,9 +10,11 @@ per-file default_web_app_ids.h=jshikaram@chromium.org
 
 per-file *wallpaper*=file://ash/wallpaper/OWNERS
 
-# input method related reviewers. shuchen@ is primary, and googleo@ is backup.
-per-file input_method*=shuchen@chromium.org
+# input method related reviewers. keithlee@ is primary, and shuchen@ and googleo@ are backup.
 per-file input_method*=googleo@chromium.org
+per-file input_method*=keithlee@chromium.org
+per-file input_method*=shuchen@chromium.org
+per-file ime_menu*=keithlee@chromium.org
 per-file ime_menu*=shuchen@chromium.org
 
 # DeviceLocalAccount reviewers. emaxx@ is primary, others are backup.