Gtk: Change NULL to nullptr

chrome/browser/ui/libgtkui/x11_input_method_context_impl_gtk.h

 // Copyright 2013 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.
 
 #ifndef CHROME_BROWSER_UI_LIBGTKUI_X11_INPUT_METHOD_CONTEXT_IMPL_GTK_H_
 #define CHROME_BROWSER_UI_LIBGTKUI_X11_INPUT_METHOD_CONTEXT_IMPL_GTK_H_
 
 #include <vector>
 
 #include "base/containers/hash_tables.h"
@@ skipping 25 matching lines @@
   void Focus() override;
   void Blur() override;
 
  private:
   // Resets the cache of X modifier keycodes.
   // TODO(yukishiino): We should call this method whenever X keyboard mapping
   // changes, for example when a user switched to another keyboard layout.
   void ResetXModifierKeycodesCache();
 
   // Constructs a GdkEventKey from a XKeyEvent and returns it.  Otherwise,
-  // returns NULL.  The returned GdkEvent must be freed by gdk_event_free.
+  // returns nullptr.  The returned GdkEvent must be freed by gdk_event_free.
   GdkEvent* GdkEventFromNativeEvent(const base::NativeEvent& native_event);
 
   // Returns true if the hardware |keycode| is assigned to a modifier key.
   bool IsKeycodeModifierKey(unsigned int keycode) const;
 
   // Returns true if one of |keycodes| is pressed.  |keybits| is a bit vector
   // returned by XQueryKeymap, and |num_keys| is the number of keys in
   // |keybits|.
   bool IsAnyOfKeycodesPressed(const std::vector<int>& keycodes,
                               const char* keybits,
@@ skipping 12 matching lines @@
                      GtkIMContext*);
   CHROMEG_CALLBACK_0(X11InputMethodContextImplGtk2,
                      void,
                      OnPreeditEnd,
                      GtkIMContext*);
   CHROMEG_CALLBACK_0(X11InputMethodContextImplGtk2,
                      void,
                      OnPreeditStart,
                      GtkIMContext*);
 
-  // A set of callback functions.  Must not be NULL.
+  // A set of callback functions.  Must not be nullptr.
   ui::LinuxInputMethodContextDelegate* delegate_;
 
   // IME's input GTK context.
   GtkIMContext* gtk_context_;
 
   gpointer gdk_last_set_client_window_;
 
   // Last known caret bounds relative to the screen coordinates.
   gfx::Rect last_caret_bounds_;
 
   // A set of hardware keycodes of modifier keys.
   base::hash_set<unsigned int> modifier_keycodes_;
 
   // A list of keycodes of each modifier key.
   std::vector<int> meta_keycodes_;
   std::vector<int> super_keycodes_;
   std::vector<int> hyper_keycodes_;
 
   DISALLOW_COPY_AND_ASSIGN(X11InputMethodContextImplGtk2);
 };
 
 }  // namespace libgtkui
 
 #endif  // CHROME_BROWSER_UI_LIBGTKUI_X11_INPUT_METHOD_CONTEXT_IMPL_GTK_H_