Multi-byte users cannot select the macro from slash command when using Firefox

Issue Summary

Multi-byte users cannot select the macro from slash command when using Firefox

Steps to Reproduce

1. Install and activate a Japanese IME(ex: https://www.google.co.jp/ime/)
2. Using Firefox, open a page
3. Type slash and "ステータス(sute-tasu)"
4. Hit Enter to confirm the character to use

Expected Results

The dropdown to select the macro will show( Chrome_expected.mov )

Actual Results

The dropdown to won't be shown and the user cannot select a macro ( actual_Firefox.mov )

Workaround

• Enter only slash and select the macro from the list
• Use Chrome