http://spywareitdaiuyfo2sqb5vsg7mek5cjabdr73luhnda57t2hyuzg7yyd.onion/articles/chrome.html
It is explained that: "When you search using the address bar in Chrome, the characters you type (even if you haven’t hit "enter" yet) are sent to your default search engine. If Google is your default search engine, predictions are based on your own search history, topics related to what you’re typing and what other people are searching for."