Chrome version:65.0.3325.65 (Official Build) beta (32 bit)
Platform: 10323.30.0
ARC: 4598704

Summary
Unable to use Japanese IME on ARC++ apps (for example, MS Excel).
Sometimes it is enabled, but after typing few characters, an app randomly lose the IME capability, so users cannot input Japanese characters anymore.

What steps will reproduce the problem?
1. Install ARC++ app (e.g. MS Word, MS Excel, memo apps (It happens on not only MS Office but also other ARC++ apps).)
2. Launch the app, and create a new doc
3. Unable to use Japanese IME

NOTE:
Chrome Input method has been configured as follows: 
- Japanese Keyboard, 
- Google Japanese Input (for Japanese Keyboard)

What is the expected output?
- Able to input Japanese via IME

What do you see instead?
- Unable to use Japanese IME. We can only input English letters.

How often does it reproduce? (Always, sometimes, hard to reproduce?)
Always