Steps to reproduce:
1. Make sure that http://www.yahoo.co.jp is in your history.
2. Switch to Kotoeri.
3. Open a new window with http://www.yahoo.co.jp from history menu.
4. Type "ka"
Results: "k" is Roman.
Alternative steps to reproduce:
1. Switch to Kotoeri.
2. Load http://www.yahoo.co.jp.
3. When the search field is already visible, but does not appear focused yet, press "k".
Results: "k" is not underlined.
Created attachment 242964 [details]
Comment on attachment 242964 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=242964&action=review
Looks good to me. Please change the title in ChangeLog before landing.
> + Kotoeri conversion sometimes decides only first character automatically in Safari 7.1 or 6.2
Not sure this clear.