How do I determine which app is trying to invoke Google Chrome?
Two places come to mind immediately.


Start up Safari and make sure Google Chrome isn't the default browser.
Clean up your launch services database.


Since you have already done #1 - redoing it won't likely matter but your safari pref file storing this setting could be corrupt.

Item 2 needs more explanation - Use Finder to right click on a text or html file - if you still see Chrome in the Open With... dialog you might want to manually rebuild the launch services database.