This is a different case.
I checked the index.html file of clock app, and found that there is actually no frame tag. This repeat-select(as well as sound selector and snooze selector) is actually a css selector we implemented by ourself. The script location is /gaia/gaia/apps/system/js/value_selector/value_selector.js. 
The new page after tap on the repeat menu is actually a Dialog, the selectors are some listbox inside the dialog, and the OK button is a submit button. (Please see style file /home/jwang/gaia/gaia/apps/system/style/bb/value_selector.css) 

Currently, I still cannot figure out a way to make it work. Zac, do you have some insights about this?