I could think of two methods:
The address bar can be put into "search mode" by one of the following:
- Ctrl + K
- Type "?" as first character
Everything thereafter will be searched for.
Change Google keyword
What you describe is usage of keywords, they used to make a quick search using another search engine. For example I use "wp Trees" to search for trees on wikipedia and "ud Tree" to search UrbanDictionary for the same.
In your case "Google" is the keyword for search using google. Change it in Settins->Basic(first Tab), find the header Search, click on the "Manage" button and you will be presented with a list of search engines to edit.
You can see that the keyword is in effect after typing the keyword, space and the first letter in your search, the addressbar left side changes to a blue frame around the search engine.