Replace static_cast<Element*> with toElement

Source/core/dom/Element.h

Index: Source/core/dom/Element.h
diff --git a/Source/core/dom/Element.h b/Source/core/dom/Element.h
index 81e6dde4bddc8c02306c53fe2a4108e9fbdddd24..b0d65736716bd32dac6cbc37981b523546773397 100644
--- a/Source/core/dom/Element.h
+++ b/Source/core/dom/Element.h
@@ -771,7 +771,7 @@ inline Element* Node::previousElementSibling() const
     Node* n = previousSibling();
     while (n && !n->isElementNode())
         n = n->previousSibling();
-    return static_cast<Element*>(n);
+    return toElement(n);
 }
 
 inline Element* Node::nextElementSibling() const
@@ -779,7 +779,7 @@ inline Element* Node::nextElementSibling() const
     Node* n = nextSibling();
     while (n && !n->isElementNode())
         n = n->nextSibling();
-    return static_cast<Element*>(n);
+    return toElement(n);
 }
 
 inline bool Element::fastHasAttribute(const QualifiedName& name) const