WakaTime

The WakaTime plugin works with Google Chrome Browser and is open source on GitHub.

The Chrome extension shows the time you spend reading documentation, debugging a web app, and other browser based activity.

Warning: The Chrome extension is still a work-in-progress, and may not play nice with your other editor-based WakaTime plugins.

Note: Activity from this Chrome extension will not display on leaderboards, so installing this extension may lower your rank.

Install the Chrome Extension:
Login to WakaTime.
Use Chrome like normal and your time will be tracked automatically on your https://wakatime.com/dashboard.

WakaTime for Chrome