What is the location of firefox extension files on Mac OSx?

I am having an issue with Selenium IDE extension. I get following error for typeKeys command

(ff22, Selenium IDE 2.1.0)

[error] Unexpected Exception: fileName -> chrome://selenium-ide/content/selenium-core/scripts/htmlutils.js, lineNumber -> 340, columnNumber -> 8

I want to know the location of : chrome://selenium-ide/content/selenium-core/scripts/htmlutils.js

the extension directory looks sth like this:

enter image description here

Neither of the folder has the desired file :(

Solution

The extensions are packaged. That file is inside one of those .xpi files (highligh-elements_selenium-ide@Samit.badle.xpi?).

You can change the .xpi extension to .zip and extract the files and you should be able to see that file.