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

Source/core/layout/FloatingObjects.cpp

Index: Source/core/layout/FloatingObjects.cpp
diff --git a/Source/core/layout/FloatingObjects.cpp b/Source/core/layout/FloatingObjects.cpp
index e66ab9afcd87c414ec3412e2c6eba190166a192e..39c6ebd230e64695261d2c9b13b8fcc9b1816008 100644
--- a/Source/core/layout/FloatingObjects.cpp
+++ b/Source/core/layout/FloatingObjects.cpp
@@ -43,7 +43,7 @@ static_assert(sizeof(FloatingObject) == sizeof(SameSizeAsFloatingObject), "Float
 
 FloatingObject::FloatingObject(LayoutBox* layoutObject)
     : m_layoutObject(layoutObject)
-    , m_originatingLine(0)
+    , m_originatingLine(nullptr)
     , m_paginationStrut(0)
     , m_shouldPaint(true)
     , m_isDescendant(false)
@@ -62,7 +62,7 @@ FloatingObject::FloatingObject(LayoutBox* layoutObject)
 
 FloatingObject::FloatingObject(LayoutBox* layoutObject, Type type, const LayoutRect& frameRect, bool shouldPaint, bool isDescendant)
     : m_layoutObject(layoutObject)
-    , m_originatingLine(0)
+    , m_originatingLine(nullptr)
     , m_frameRect(frameRect)
     , m_paginationStrut(0)
     , m_type(type)
@@ -107,7 +107,7 @@ public:
         , m_lineTop(lineTop)
         , m_lineBottom(lineBottom)
         , m_offset(offset)
-        , m_outermostFloat(0)
+        , m_outermostFloat(nullptr)
     {
     }
 
@@ -169,7 +169,7 @@ void FloatingObjects::clearLineBoxTreePointers()
     FloatingObjectSetIterator end = m_set.end();
     for (FloatingObjectSetIterator it = m_set.begin(); it != end; ++it) {
         ASSERT(!((*it)->originatingLine()) || (*it)->originatingLine()->layoutObject() == m_layoutObject);
-        (*it)->setOriginatingLine(0);
+        (*it)->setOriginatingLine(nullptr);
     }
 }