Based on the provided text, it is difficult to determine the exact topic or purpose of the website. The text includes a combination of code snippets and various function calls related to performance measurement and browser compatibility. It seems to be discussing functions and operations related to web performance, polyfills for different browsers, error handling, and some undefined variables. However, without more context or additional information about the website's content, it is not possible to provide a comprehensive summary of what the site is specifically about.
