Resize Window To Element автор Jesper S

Does what it says on the tin. Right click > Resize To Element and then you get to select your element with a picker. Some resize behaviors are available in the extension options

Can also be started from the extensions in toolbar simply by clicking the extension.

I used an element picker like this so that you can use it on elements that normally don't let you right click, such as video players and whatnot.

If anything is wonky with the padding, go ahead and check the settings-- you can manually set width/height for overall padding as well as for scroll bars (in case you don't have 17px like I do)