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

Source/core/layout/LayoutMultiColumnSet.cpp

 /*
  * Copyright (C) 2012 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 17 matching lines @@
 
 #include "core/editing/PositionWithAffinity.h"
 #include "core/layout/LayoutMultiColumnFlowThread.h"
 #include "core/layout/MultiColumnFragmentainerGroup.h"
 #include "core/paint/MultiColumnSetPainter.h"
 #include "platform/RuntimeEnabledFeatures.h"
 
 namespace blink {
 
 LayoutMultiColumnSet::LayoutMultiColumnSet(LayoutFlowThread* flowThread)
-    : LayoutBlockFlow(0)
+    : LayoutBlockFlow(nullptr)
     , m_fragmentainerGroups(*this)
     , m_flowThread(flowThread)
 {
 }
 
 LayoutMultiColumnSet* LayoutMultiColumnSet::createAnonymous(LayoutFlowThread& flowThread, const ComputedStyle& parentStyle)
 {
     Document& document = flowThread.document();
     LayoutMultiColumnSet* layoutObject = new LayoutMultiColumnSet(&flowThread);
     layoutObject->setDocumentForAnonymous(&document);
@@ skipping 25 matching lines @@
     // locate the right row.
     return firstFragmentainerGroup().logicalHeight();
 }
 
 LayoutMultiColumnSet* LayoutMultiColumnSet::nextSiblingMultiColumnSet() const
 {
     for (LayoutObject* sibling = nextSibling(); sibling; sibling = sibling->nextSibling()) {
         if (sibling->isLayoutMultiColumnSet())
             return toLayoutMultiColumnSet(sibling);
     }
-    return 0;
+    return nullptr;
 }
 
 LayoutMultiColumnSet* LayoutMultiColumnSet::previousSiblingMultiColumnSet() const
 {
     for (LayoutObject* sibling = previousSibling(); sibling; sibling = sibling->previousSibling()) {
         if (sibling->isLayoutMultiColumnSet())
             return toLayoutMultiColumnSet(sibling);
     }
-    return 0;
+    return nullptr;
 }
 
 LayoutUnit LayoutMultiColumnSet::logicalTopInFlowThread() const
 {
     return firstFragmentainerGroup().logicalTopInFlowThread();
 }
 
 LayoutUnit LayoutMultiColumnSet::logicalBottomInFlowThread() const
 {
     return lastFragmentainerGroup().logicalBottomInFlowThread();
@@ skipping 222 matching lines @@
 
 LayoutRect LayoutMultiColumnSet::flowThreadPortionRect() const
 {
     LayoutRect portionRect(LayoutUnit(), logicalTopInFlowThread(), pageLogicalWidth(), logicalHeightInFlowThread());
     if (!isHorizontalWritingMode())
         return portionRect.transposedRect();
     return portionRect;
 }
 
 }