Google Chrome disable screen ruler

Since the last update of Google Chrome, a screen ruler shows up when inspecting an element. Does anyone know how to disable this ruler?

How do I remove the ruler from Chrome?

Right-click anywhere on the screen, "Inspect Element", gear-wheel in the lower left (Windows) or in the lower right (Mac), "General" tab, scroll down at the bottom "Show Rulers". Check it on/off to liking.

How do I use page ruler extension?

To activate the addon please press the toolbar button once. Likewise, to disable the addon please press the toolbar button again. This addon works with mouse clicks in desktop machines. For touch-enabled devices, you can work with touch to draw the rectangle within the page.

This is an old question, but now you can enable or disable now in Chrome Developer Tools -> Settings -> Show Rulers (you can also access the settings just pressing F1).

How to enable or disable rulers in Chrome