Computer Configuration > Administrative Templates > Google Chrome - Default Settings (users can override)
Both
HKLM\Software\Policies\Google\Chrome\Recommended
Setting the policy to True turns on search suggestions in Google Chrome's address bar. Setting the policy to False turns off these search suggestions. Suggestions based on bookmarks or history are unaffected by the policy. If you set the policy, users can't change it. If not set, search suggestions are on at first, but users can turn them off any time.