Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/html/shadow/MediaControlElements.cpp

 /*
  * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2012 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.
@@ skipping 107 matching lines @@
 {
     if (!m_isBeingDragged)
         return;
 
     m_isBeingDragged = false;
 
     Frame* frame = document().frame();
     if (!frame)
         return;
 
-    frame->eventHandler().setCapturingMouseEventsNode(0);
+    frame->eventHandler().setCapturingMouseEventsNode(nullptr);
 }
 
 void MediaControlPanelElement::startTimer()
 {
     stopTimer();
 
     // The timer is required to set the property display:'none' on the panel,
     // such that captions are correctly displayed at the bottom of the video
     // at the end of the fadeout transition.
     // FIXME: Racing a transition with a setTimeout like this is wrong.
@@ skipping 607 matching lines @@
     float fontSize = smallestDimension * 0.05f;
     if (fontSize != m_fontSize) {
         m_fontSize = fontSize;
         setInlineStyleProperty(CSSPropertyFontSize, fontSize, CSSPrimitiveValue::CSS_PX);
     }
 }
 
 // ----------------------------
 
 } // namespace WebCore