Gtk: Change NULL to nullptr

chrome/browser/ui/libgtkui/gtk_util.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_util.h"
 
 #include <dlfcn.h>
 #include <gdk/gdk.h>
 #include <gdk/gdkx.h>
 #include <gtk/gtk.h>
@@ skipping 22 matching lines @@
 void CommonInitFromCommandLine(const base::CommandLine& command_line,
                                void (*init_func)(gint*, gchar***)) {
   const std::vector<std::string>& args = command_line.argv();
   int argc = args.size();
   std::unique_ptr<char* []> argv(new char*[argc + 1]);
   for (size_t i = 0; i < args.size(); ++i) {
     // TODO(piman@google.com): can gtk_init modify argv? Just being safe
     // here.
     argv[i] = strdup(args[i].c_str());
   }
-  argv[argc] = NULL;
+  argv[argc] = nullptr;
   char** argv_pointer = argv.get();
 
   {
     // http://crbug.com/423873
     ANNOTATE_SCOPED_MEMORY_LEAK;
     init_func(&argc, &argv_pointer);
   }
   for (size_t i = 0; i < args.size(); ++i) {
     free(argv[i]);
   }
@@ skipping 142 matching lines @@
   // the two later.
   g_object_set_data(G_OBJECT(dialog), kAuraTransientParent, parent);
 }
 
 aura::Window* GetAuraTransientParent(GtkWidget* dialog) {
   return reinterpret_cast<aura::Window*>(
       g_object_get_data(G_OBJECT(dialog), kAuraTransientParent));
 }
 
 void ClearAuraTransientParent(GtkWidget* dialog) {
-  g_object_set_data(G_OBJECT(dialog), kAuraTransientParent, NULL);
+  g_object_set_data(G_OBJECT(dialog), kAuraTransientParent, nullptr);
 }
 
 #if GTK_MAJOR_VERSION > 2
 CairoSurface::CairoSurface(SkBitmap& bitmap)
     : surface_(cairo_image_surface_create_for_data(
           static_cast<unsigned char*>(bitmap.getAddr(0, 0)),
           CAIRO_FORMAT_ARGB32,
           bitmap.width(),
           bitmap.height(),
           cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, bitmap.width()))),
@@ skipping 330 matching lines @@
   }
 
   CairoSurface surface(gfx::Size(w, h));
   gtk_render_background(context, surface.cairo(), 0, 0, w, h);
   gtk_render_frame(context, surface.cairo(), 0, 0, w, h);
   return surface.GetAveragePixelValue(false);
 }
 #endif
 
 }  // namespace libgtkui