WIP (Introduce WTF::NonNullPtr<T>.)

Source/core/svg/SVGElement.cpp

Index: Source/core/svg/SVGElement.cpp
diff --git a/Source/core/svg/SVGElement.cpp b/Source/core/svg/SVGElement.cpp
index 9524f055b4304ffb9ae56f6f324016bece807b96..95d122eb6ed303dcd71ad7e3000311643e84e3bc 100644
--- a/Source/core/svg/SVGElement.cpp
+++ b/Source/core/svg/SVGElement.cpp
@@ -236,7 +236,7 @@ String SVGElement::title() const
 
     // Walk up the tree, to find out whether we're inside a <use> shadow tree, to find the right title.
     if (isInShadowTree()) {
-        Element* shadowHostElement = toShadowRoot(treeScope().rootNode())->host();
+        Element* shadowHostElement = toShadowRoot(treeScope()->rootNode())->host();
         // At this time, SVG nodes are not allowed in non-<use> shadow trees, so any shadow root we do
         // have should be a use. The assert and following test is here to catch future shadow DOM changes
         // that do enable SVG in a shadow tree.