For which browser is it easier to write extensions for Firefox or Chrome?

Question

Google Chrome

I want to write an extension for tricky form filling. But I do not have enough time, so I would like to ask people who have experience in developing for these two browsers: "For which browser is it easier to write extensions faster?"
PS The extension will fill out forms in a semi-manual form, that is, I myself will call it with a hot button from the page. It will pop up a window to search for a template alias based on a prefix tree (like sublime text files are quick to open). And fill in one field at once part of the form.

Answer 1

Definitely Chrome!

Answer 2

If the filling is not tricky, you can take firefox + vimperator and just make a macro.