ace2_inner: remove Chrome specific hack
ace2_inner: remove Chrome specific hack

This code was specific for older Chrome versions. It can be simplified now.

Fixes #3487
ether/etherpad-lite,ether/etherpad-lite,storytouch/etherpad-lite,storytouch/etherpad-lite,joequant/etherpad-lite,joequant/etherpad-lite,joequant/etherpad-lite,storytouch/etherpad-lite,joequant/etherpad-lite,ether/etherpad-lite