Gtk: Change NULL to nullptr

chrome/browser/ui/libgtkui/gtk_key_bindings_handler.h

Index: chrome/browser/ui/libgtkui/gtk_key_bindings_handler.h
diff --git a/chrome/browser/ui/libgtkui/gtk_key_bindings_handler.h b/chrome/browser/ui/libgtkui/gtk_key_bindings_handler.h
index 4c0cf02acf4461925aa8c8020b5fee0a6aebf374..6794cc22de8c1e59721d3ed24174f102a0228b20 100644
--- a/chrome/browser/ui/libgtkui/gtk_key_bindings_handler.h
+++ b/chrome/browser/ui/libgtkui/gtk_key_bindings_handler.h
@@ -46,7 +46,7 @@ class Gtk2KeyBindingsHandler {
   // Matches a key event against predefined gtk key bindings, false will be
   // returned if the key event doesn't correspond to a predefined key binding.
   // Edit commands matched with |event| will be stored in |edit_commands|, if
-  // non-NULL.
+  // non-nullptr.
   bool MatchEvent(const ui::Event& event,
                   std::vector<ui::TextEditCommandAuraLinux>* commands);