Comment 6 for bug 863192

Confirmed that this is still a problem in 12.04. It's definitely the same as http://code.google.com/p/chromium/issues/detail?id=98869. When a pinned tab starts flashing, CPU usage jumps. To bring it back down again, you have to select the pinned tab, then select a different tab.

There's no fix yet and no option to stop pinned tabs from flashing when their content changes. The workaround is to unpin the tabs.