Speedtest by Ookla for Chrome permits you to take a speed test from your browser without interruption.

It also will measure how fast the pages you visit load with Web Speed which is a neat little feature. Speedtest by Ookla for Chrome looks like the standard webpage associated with Ookla's Speedtest except smaller. The nice thing is that you do not need to navigate away from what you are doing. You just tap the extension's icon and hit go.

Speedtest by Ookla for Chrome Features:

Get your ping, download, and upload speeds within seconds
Measure how fast websites load

Permissions:

Chrome will ask for permission to "Read and change all your data on the websites you visit". Speedtest also measures how fast websites load with Web Speed, and it uses this permission to know how long it takes a given website to load. You can disable Web Speed in the extension settings.