Fixes for old webkit inspector versions in chromium.

webkitInspector.user.js

// ==UserScript==
// @name        Webkit Inspector Fix
// @namespace   Violentmonkey Scripts
// @match       http://localhost:8888/webinspector/inspector.html
// @grant       none
// @version     1.0
// @author      -
// @description 4/15/2021, 10:04:41 AM
// ==/UserScript==
CSSStyleDeclaration.prototype.getPropertyCSSValue = CSSStyleDeclaration.prototype.getPropertyValue;
CSSPrimitiveValue = String;
String.prototype.getFloatValue = function () {
  return parseFloat(this);
};
Object.defineProperty(KeyboardEvent.prototype, "keyIdentifier", {
    get : function () {
        return this.key;
    }
});