Chrome find bar closing on macOS Sierra
A simple workaround to close the find bar is to use Fn + Esc, rather then Esc.



However, you can easily prevent Chrome to close the full-sceen mode by pressing Esc through this script (following this post):

// ==UserScript==
// @name           Keep Full Screen
// @namespace     https://superuser.com/q/315949
// @description    Prevents Escape key from leaving full screen.
// @include      http://*
// ==/UserScript==
document.onkeydown = function (evt) {
    if (evt.keyCode == 27) evt.preventDefault();
}


To run this, you can use the NinjaKit Google Chrome extension.