Google Chrome now has tab grouping. In Beta, you can click on the group name and collapse the tabs. Based on their reload times, it seems chrome suspends the tabs in the background when you collapse the group.
This looks promising. To activate the suspend on collapse feature enter "chrome://flags/" into the address bar and make sure these experimental features are "enabled": #tab-groups, #tab-groups-collapse, #tab-groups-collapse-freezing. I also enabled: #tab-groups-auto-create.
