Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/modules/gamepad/NavigatorGamepad.cpp

 /*
  * Copyright (C) 2011, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 38 matching lines @@
             gamepad->index(i);
             gamepad->connected(webGamepad.connected);
             gamepad->timestamp(webGamepad.timestamp);
 #if defined(ENABLE_NEW_GAMEPAD_API)
             gamepad->mapping(webGamepad.mapping);
 #endif
             gamepad->axes(webGamepad.axesLength, webGamepad.axes);
             gamepad->buttons(webGamepad.buttonsLength, webGamepad.buttons);
             into->set(i, gamepad);
         } else {
-            into->set(i, 0);
+            into->set(i, nullptr);
         }
     }
 }
 
 NavigatorGamepad::NavigatorGamepad()
 {
 }
 
 NavigatorGamepad::~NavigatorGamepad()
 {
@@ skipping 21 matching lines @@
 
 GamepadList* NavigatorGamepad::gamepads()
 {
     if (!m_gamepads)
         m_gamepads = GamepadList::create();
     sampleGamepads(m_gamepads.get());
     return m_gamepads.get();
 }
 
 } // namespace WebCore