How to Pause & Save Videos to Watch Later From Where You Left Off

You have to add the extension called Pause For Later.

Pause For Later is a Chrome extension that allows you to pause videos and save them for watching later.
After installing the extension, click the button in the toolbar to pause and save videos. Moreover, videos are saved along with the Time Remaining, Paused and Position information. You may watch videos right from where you left off.

It also records how much of a video you’ve watched

This extension also available for Firefox, Safari.