A blast from the past! I, too, was messing with system fonts in Ubuntu and ended up with the Chrome address bar stuck at a too-small size and not paying attention to changes in system font size configured in Tweaks. Neither clearing cache, removing/reinstalling google-chrome-stable or deleting the user profile folder fixed it.
What did fix it was restoring the system font to the original (and aptly-named default) font "Ubuntu regular". And you have to exit and restart the browser for the config change to take effect.
I guess Chrome does pick up the name of the system font but ignores the system configured font size when rendering the address bar. Evidence: When I change the system font size in Tweaks then restart Chrome, it is using the new size in tabs, bookmark bar, hover text and others, but not in address bar, application list (9 blocks).
Now, why the one-and-only size is OK for the default system font (Ubuntu) but not for, say Umpush and the few others I happened to try, I cannot say. All of these are True Type fonts, so I do not believe they have any native default size.
Since Chromium is reported to have the same behavior (I have not confirmed), why doesn't some public spirited dev offer a PR to
~/.config/gtk-3.0/settings.ini. Not all fonts of the same "size" appear visually of the same size. You can find the "largest" one by having the same text in several line in LibO Writer and testing different fonts. You'll see a difference. Choose the one you like. As a user that's about all you can do. The font-size in Chrome's urlbar has been a
WontFixfor years :(