Assume all providers may give zero suggest responses.

chrome/browser/autocomplete/shortcuts_provider.h

Index: chrome/browser/autocomplete/shortcuts_provider.h
diff --git a/chrome/browser/autocomplete/shortcuts_provider.h b/chrome/browser/autocomplete/shortcuts_provider.h
index 848fa5333d65ef69c2d2126796c8964b34afc787..24665a7dbb7c2599ee7c9008adedc89667159b52 100644
--- a/chrome/browser/autocomplete/shortcuts_provider.h
+++ b/chrome/browser/autocomplete/shortcuts_provider.h
@@ -28,7 +28,9 @@ class ShortcutsProvider
 
   // Performs the autocompletion synchronously. Since no asynch completion is
   // performed |minimal_changes| is ignored.
-  void Start(const AutocompleteInput& input, bool minimal_changes) override;
+  void Start(const AutocompleteInput& input,
+             bool minimal_changes,
+             bool on_focus) override;
 
   void DeleteMatch(const AutocompleteMatch& match) override;