In order to avoid to see file type as "...." in Open File dialog. bug31382. "All Files", "HTML Files (*.htm;, *.html)", "Text Files(*.txt)" should replace to English for Beta1 JA.
Note this is just a workaround for Beta1 localizations. Once bug 31382 is fixed, we should translate these strings from English.
I verified this in 2000032417 Ja build.