When I first saw the Chrome update, I thought: "Hey, it looks just like Firefox!"
Sorry, if that was your thought, I’m afraid all design is probably lost on you. Which might be a blessing, since you can use whatever and can’t tell the difference anyway.
It can be switched back (for now)...
Go to chrome://flags, search for "UI Layout for the browser's top chrome" and pick "Normal". Restart and enjoy the old design.