Luckily in Slimjet browser here's a simple way to let us set the Address bar to resize as we add more buttons. Click the little black arrow to the right of your toolbar buttons and choose:
'Show toolbar buttons on left'
Now the Tool Bar buttons are grouped to the left of the Address Bar, and the address bar will resize as we move more buttons into and out of the Toolbar.
Quick, Simple and Effective.
There are many posts on the web asking how to resize the Address bar to make room for buttons. i have not yet seen a post on this method that I use in Slimjet, and I have no idea if it can be used in Chrome, Chromium or any other browser.
But if you have those little black arrows at the end of your Tool button bar, there's a good chance the option to move the buttons left or right will do the same thing on those browsers.