You neither have to install any software on your computer nor any extensions in your browser because Google Chrome itself acts as the PDF writer.
This is especially useful for downloading PDF copies of web pages that involve transactions or session data – like the checkout page on a shopping website – because you often cannot pass such pages to any online PDF conversion service.
One more thing. You can also use Chrome’s PDF engine to convert your local image files, text files and any local HTML web pages to PDFs – if you an open a file in Chrome, it can convert the file to PDF.