Restrict Chrome's Omibox Suggestions to Web Searches
What to do if you only want to see web search suggestions in Chrome's omnibox, not suggestions from Google's top results, your bookmarks, your browsing history or previously typed URLs. Type ? in the omnibox and then start typing your query. You can also use these keyboard shortcuts: Ctrl+K or Ctrl+E for Windows and Linux, ⌘-Option-F for Mac.
Chrome will still show suggestions from your previous searches. If you use this trick in the incognito mode, Chrome will only show suggestions from your search history.