Assume all providers may give zero suggest responses.

chrome/browser/autocomplete/autocomplete_controller.h

Index: chrome/browser/autocomplete/autocomplete_controller.h
diff --git a/chrome/browser/autocomplete/autocomplete_controller.h b/chrome/browser/autocomplete/autocomplete_controller.h
index cd808884fa33da2378be28b0cec587e9a80aa893..08b1164448c35fa355c0cf0182bdd303999db9df 100644
--- a/chrome/browser/autocomplete/autocomplete_controller.h
+++ b/chrome/browser/autocomplete/autocomplete_controller.h
@@ -81,9 +81,9 @@ class AutocompleteController : public AutocompleteProviderListener {
   void Stop(bool clear_result);
 
   // Called when the omnibox is focused while no existing user input is in
-  // progress.  This is used to trigger any providers which want to provide
-  // matches in response to focus.  See
-  // AutocompleteProvider::ProvidesMatchesOnOmniboxFocus().
+  // progress.  This is used to call Start() on all providers with
+  // |called_due_to_focus| parameter set to check if they want to provide
+  // on focus matches.
   void OnOmniboxFocused(const AutocompleteInput& input);
 
   // Asks the relevant provider to delete |match|, and ensures observers are