Download Resumption is an experimental feature for Chrome 29. You can enable this feature from Chrome ?ags on Mac, Windows, Linux, and Chrome OS. Just type chrome://flags in the address bar and hit enter. Now, search for Download Resumption option, enable it and relaunch Chrome. Now, Chrome allow downloads that have been interrupted to be continued or restarted, using the Resume context menu item.

Keep in mind that Chrome ?ags are part of the Chrome Beta version of the browser. It is experimental and may not work as we expect, so proceed with caution.