If you're a Google chrome user on Ubuntu you may have noticed apt-get update seems to wait around for two minutes sitting at 99%. The culprit is the google apt repo having issues with http/1.1 pipelining. Fortunately there's a bug for it on Launchpad with a workaround that does the job. Thanks gozdal!
The solution boils down to turning off http/1.1 pipelining. Here's how (note the bug listed above lists the incorrect path to the conf dir):
Open /etc/apt/apt.conf.d/google-workaround.conf with your favorite editor. (You'll need sudo e.g. sudo vim or gksudo gedit).
Add the following line:
Acquire::http::Pipeline-Depth "0";Save it and run sudo apt-get upgrade again and you should find it completes without the 2 minute delay.