[Mac] Don't eat tab if tab-to-search hint not visible.

chrome/browser/autocomplete/autocomplete_edit_view_mac.h

Index: chrome/browser/autocomplete/autocomplete_edit_view_mac.h
diff --git a/chrome/browser/autocomplete/autocomplete_edit_view_mac.h b/chrome/browser/autocomplete/autocomplete_edit_view_mac.h
index aac879b846a51b19253bdd4876521b9431047f8f..0c0cb2bdc8caa9996fcc4c67762861a8daac2b83 100644
--- a/chrome/browser/autocomplete/autocomplete_edit_view_mac.h
+++ b/chrome/browser/autocomplete/autocomplete_edit_view_mac.h
@@ -112,10 +112,11 @@ class AutocompleteEditViewMac : public AutocompleteEditView {
   // Called when the user attempts to paste into |field_|.
   void OnPaste();
 
-  void AcceptInput(WindowOpenDisposition disposition, bool for_drop);
+  // Checks if a keyword search is possible and forwards to |model_|
+  // if so.  Returns true if the tab should be eaten.
+  bool OnTabPressed();
 
-  // Forwards to |model_| when user hits Tab.
-  void AcceptKeyword();
+  void AcceptInput(WindowOpenDisposition disposition, bool for_drop);
 
   // Helper for LocationBarViewMac.  Selects all in |field_|.
   void FocusLocation();