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

Source/core/layout/svg/LayoutSVGInlineText.cpp

Index: Source/core/layout/svg/LayoutSVGInlineText.cpp
diff --git a/Source/core/layout/svg/LayoutSVGInlineText.cpp b/Source/core/layout/svg/LayoutSVGInlineText.cpp
index 69a3b61ad7496474fa1ae2a32ff77a7ea4af2da2..5274a5264e124fcb8913083bfac7b99c31d35fa1 100644
--- a/Source/core/layout/svg/LayoutSVGInlineText.cpp
+++ b/Source/core/layout/svg/LayoutSVGInlineText.cpp
@@ -175,8 +175,8 @@ PositionWithAffinity LayoutSVGInlineText::positionForPoint(const LayoutPoint& po
 
     float closestDistance = std::numeric_limits<float>::max();
     float closestDistancePosition = 0;
-    const SVGTextFragment* closestDistanceFragment = 0;
-    SVGInlineTextBox* closestDistanceBox = 0;
+    const SVGTextFragment* closestDistanceFragment = nullptr;
+    SVGInlineTextBox* closestDistanceBox = nullptr;
 
     AffineTransform fragmentTransform;
     for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {