I just did this successfully after the described methods above failed. (I could not push, fetch, or manually refresh)
Note; this is not a refresh, but a quick delete / re-install
1) settings; icloud; mail off, calendars off. (temporary, and not sure it's neccessary)
2) back to settings; mail contacts calendars; gmail account; delete.
3) add acount; reinstall your google account! (only took a few seconds to load everything back from google servers)
4) turn your icloud back ups on again if you wish and back up new data. I dont need to back up my gmail neccessarily, neither my calendar, now that I know how to reload direct from Google.
Why I wanted to figure this out;
I got an I phone replacement, (Thank you Apple!) but my i-cloud backup had filled up over a month ago, ( I chose to ignore) so I lost only the new data up to today's replacement ( calendar entries, texts, a new contact or two, and a month's worth of the only game I play.. real racing 3.. errr..so i just deleted the game:-)
This worked for me in iOS8 as well.
Tapped "Calendars" at the bottom, then pulled down to refresh the Calendars screen and all my Google calendars that were set to share (https://www.google.com/calendar/syncselect) appeared. I viewed my calendars and there were still no appointments. I wend back to "Calendars" at the bottom and pulled down to refresh the Calendars a second time. Tapped back to view my calendars, and all my data was there.