Auto Tab Discard by Richard Neomy

Auto Tab Discard a lightweight extension that automatically reduces the memory load of open—but inactive—tabs. This also helps portable devices to save battery.

Extension preview:
https://www.youtube.com/watch?v=S0rHU38OnTE
https://www.youtube.com/watch?v=ityhxUPp3y8

Features:
1. Speeds up your browser and minimizes memory usage: Inactive, idle, or forgotten tabs can be auto-discarded after a configurable period of time, or discarded manually from the toolbar menu.
2. Designate specific tabs (websites) to be whitelisted to prevent discarding.
3. Discarded tabs can be retained after closing and re-opening your browser.
4. The tab’s favicon displays the discarded state.
5. Tabs are restored with all information intact (like scroll position or the content of text boxes).
6. When a tab is discarded, no JavaScript code or dom event is active (basically, the tab is paused).
7. Force discarding certain hostnames (e.g. you can immediately discard hostnames that use too much CPU or memory)

Options (there are a few options to customize when a tab gets discarded):
1. When a tab is pinned
2. When there is a media source playing inside a tab
3. When the computer is connected to a power source
4. When there is a form element (with changes) that has not yet been submitted.