If you type into Chrome's URL/browser bar, it sends the query to google's servers which in turn returns a list of possible search suggestions (autocomplete style). Google likely retains the query for commercialisation purposes.
So the user being worried about a Chrome plugin sending browsing data seems bizarre.
So, when I click a link on HN, using Chrome, Chrome is sending that information to Google? Likewise when I type http://somethingorother, that's going through Google first?