Generally when you print a regular webpage (HTML file), you get some options in the Google Chrome print page dialog:
Headers and footers: Choose whether to include a default header and footer that display the date, page title, URL, and number of pages
Two-sided: Choose this option to print on both sides of the paper if you have a duplex printer.
Print using system dialog (except Chrome OS): Use your operating system's print functionality instead of Chrome's functionality to
print the page.
Selecting the Headers and footers would do exactly what you need to achieve - it will show the webpage URL in the footer (as well as some other data in the header and in the footer, as mentioned above).
However, when printing a pdf file in Chrome, you only get two options: Fit to page & Two-Sided. You can't include headers and footers in the pdf file.
So far I haven't found any simple workarounds to solve this. Using Adobe PDF viewer instead of Chrome's or using the default printer dialog won't help.
The only solution I found so far is to either download the pdf file to your computer (by right clicking the pdf page and clicking "Save as...") and edit it in a PDF manager/editor like Adobe Acrobat, or to edit the pdf file online, copy the URL of the pdf file, add it to the pdf file (where ever you want) and print it. Both will work.