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

Source/core/layout/svg/SVGTextLayoutEngine.cpp

Index: Source/core/layout/svg/SVGTextLayoutEngine.cpp
diff --git a/Source/core/layout/svg/SVGTextLayoutEngine.cpp b/Source/core/layout/svg/SVGTextLayoutEngine.cpp
index d9f503570a027ef551bc52c8bcc56526726a4c85..fae2e5e9dfdec02087796189bdbca84471cc1839 100644
--- a/Source/core/layout/svg/SVGTextLayoutEngine.cpp
+++ b/Source/core/layout/svg/SVGTextLayoutEngine.cpp
@@ -45,7 +45,7 @@ SVGTextLayoutEngine::SVGTextLayoutEngine(Vector<SVGTextLayoutAttributes*>& layou
     , m_isVerticalText(false)
     , m_inPathLayout(false)
     , m_textLengthSpacingInEffect(false)
-    , m_textPathCalculator(0)
+    , m_textPathCalculator(nullptr)
     , m_textPathLength(0)
     , m_textPathCurrentOffset(0)
     , m_textPathSpacing(0)
@@ -360,7 +360,7 @@ void SVGTextLayoutEngine::layoutTextOnLineOrPath(SVGInlineTextBox* textBox, cons
             continue;
         }
 
-        SVGTextLayoutAttributes* logicalAttributes = 0;
+        SVGTextLayoutAttributes* logicalAttributes = nullptr;
         if (!currentLogicalCharacterAttributes(logicalAttributes))
             break;