C++11: Replace 0 with nullptr where applicable in layout code.

Source/core/layout/LayoutVideo.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010 Apple 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 108 matching lines @@
     if (videoElement()->shouldDisplayPosterImage())
         m_cachedImageSize = intrinsicSize();
 
     // The intrinsic size is now that of the image, but in case we already had the
     // intrinsic size of the video we call this here to restore the video size.
     updateIntrinsicSize();
 }
 
 IntRect LayoutVideo::videoBox() const
 {
-    const LayoutSize* overriddenIntrinsicSize = 0;
+    const LayoutSize* overriddenIntrinsicSize = nullptr;
     if (videoElement()->shouldDisplayPosterImage())
         overriddenIntrinsicSize = &m_cachedImageSize;
 
     return pixelSnappedIntRect(replacedContentRect(overriddenIntrinsicSize));
 }
 
 bool LayoutVideo::shouldDisplayVideo() const
 {
     return !videoElement()->shouldDisplayPosterImage();
 }
@@ skipping 57 matching lines @@
 
 bool LayoutVideo::supportsAcceleratedRendering() const
 {
     return !!mediaElement()->platformLayer();
 }
 
 static const LayoutBlock* layoutObjectPlaceholder(const LayoutObject* layoutObject)
 {
     LayoutObject* parent = layoutObject->parent();
     if (!parent)
-        return 0;
+        return nullptr;
 
     LayoutFullScreen* fullScreen = parent->isLayoutFullScreen() ? toLayoutFullScreen(parent) : 0;
     if (!fullScreen)
-        return 0;
+        return nullptr;
 
     return fullScreen->placeholder();
 }
 
 LayoutUnit LayoutVideo::offsetLeft() const
 {
     if (const LayoutBlock* block = layoutObjectPlaceholder(this))
         return block->offsetLeft();
     return LayoutMedia::offsetLeft();
 }
@@ skipping 27 matching lines @@
             return CompositingReasonVideo;
     }
 
     if (shouldDisplayVideo() && supportsAcceleratedRendering())
         return CompositingReasonVideo;
 
     return CompositingReasonNone;
 }
 
 } // namespace blink