Gtk: Change NULL to nullptr

chrome/browser/ui/libgtkui/gtk_key_bindings_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/libgtkui/gtk_key_bindings_handler.h"
 
 #include <gdk/gdkkeysyms.h>
 #include <X11/Xlib.h>
 #include <stddef.h>
 #include <X11/XKBlib.h>
@@ skipping 63 matching lines @@
       &gdk_event);
 
   bool matched = !edit_commands_.empty();
   if (edit_commands)
     edit_commands->swap(edit_commands_);
   return matched;
 }
 
 GtkWidget* Gtk2KeyBindingsHandler::CreateNewHandler() {
   Handler* handler =
-      static_cast<Handler*>(g_object_new(HandlerGetType(), NULL));
+      static_cast<Handler*>(g_object_new(HandlerGetType(), nullptr));
 
   handler->owner = this;
 
   // We don't need to show the |handler| object on screen, so set its size to
   // zero.
   gtk_widget_set_size_request(GTK_WIDGET(handler), 0, 0);
 
   // Prevents it from handling any events by itself.
   gtk_widget_set_sensitive(GTK_WIDGET(handler), FALSE);
   gtk_widget_set_events(GTK_WIDGET(handler), 0);
@@ skipping 31 matching lines @@
       NOTIMPLEMENTED();
       logged = true;
     }
     gdk_event->group = 0;
   }
 
   gdk_event->keyval = GDK_KEY_VoidSymbol;
   gdk_keymap_translate_keyboard_state(
       keymap, gdk_event->hardware_keycode,
       static_cast<GdkModifierType>(gdk_event->state), gdk_event->group,
-      &gdk_event->keyval, NULL, NULL, &consumed);
+      &gdk_event->keyval, nullptr, nullptr, &consumed);
 
   state = static_cast<GdkModifierType>(gdk_event->state & ~consumed);
   gdk_keymap_add_virtual_modifiers(keymap, &state);
   gdk_event->state |= state;
 }
 
 void Gtk2KeyBindingsHandler::HandlerInit(Handler* self) {
-  self->owner = NULL;
+  self->owner = nullptr;
 }
 
 void Gtk2KeyBindingsHandler::HandlerClassInit(HandlerClass* klass) {
   GtkTextViewClass* text_view_class = GTK_TEXT_VIEW_CLASS(klass);
   GtkWidgetClass* widget_class = GTK_WIDGET_CLASS(klass);
 
   // Overrides all virtual methods related to editor key bindings.
   text_view_class->backspace = BackSpace;
   text_view_class->copy_clipboard = CopyClipboard;
   text_view_class->cut_clipboard = CutClipboard;
@@ skipping 270 matching lines @@
   // Just for disabling the default handler.
   return FALSE;
 }
 
 void Gtk2KeyBindingsHandler::MoveFocus(GtkWidget* widget,
                                        GtkDirectionType arg1) {
   // Just for disabling the default handler.
 }
 
 }  // namespace libgtkui