This was added to cyanogen as a status bar option. Someone send the patch to android, became a setting one of the irrelevant post-2.3 versions i believe (when m

This was added to cyanogen as a status bar option. Someone send the patch to android, became a setting one of the irrelevant post-2.3 versions i believe (when most of the code was scratched because they were forking 3 vs 4 to tweak for tablets), and disappeared on actual versions that were pushed to phones as google do with every little feature where the community do manage to overcome the immense hurdle of contributing to android in the first place. open source in android only means "carriers do not have to sign a NDA to see the source in order to send patches for OEM marketing tweaks on the UI" :(