Use tighter typing in editing: MarkupAccumulator

Source/core/page/PageSerializer.cpp

Index: Source/core/page/PageSerializer.cpp
diff --git a/Source/core/page/PageSerializer.cpp b/Source/core/page/PageSerializer.cpp
index 9ec4e243ee3dd36269945a46056344a3321b7d3f..3ad1bda6be6607f085e40ac09c09693a7fe22128 100644
--- a/Source/core/page/PageSerializer.cpp
+++ b/Source/core/page/PageSerializer.cpp
@@ -108,7 +108,7 @@ protected:
     virtual void appendText(StringBuilder& out, Text&) OVERRIDE;
     virtual void appendElement(StringBuilder& out, Element&, Namespaces*) OVERRIDE;
     virtual void appendCustomAttributes(StringBuilder& out, const Element&, Namespaces*) OVERRIDE;
-    virtual void appendEndTag(const Node&) OVERRIDE;
+    virtual void appendEndTag(const Element&) OVERRIDE;
 
 private:
     PageSerializer* m_serializer;
@@ -167,10 +167,10 @@ void SerializerMarkupAccumulator::appendCustomAttributes(StringBuilder& out, con
     appendAttribute(out, element, Attribute(frameOwnerURLAttributeName(frameOwner), AtomicString(url.string())), namespaces);
 }
 
-void SerializerMarkupAccumulator::appendEndTag(const Node& node)
+void SerializerMarkupAccumulator::appendEndTag(const Element& element)
 {
-    if (node.isElementNode() && !shouldIgnoreElement(toElement(node)))
-        MarkupAccumulator::appendEndTag(node);
+    if (!shouldIgnoreElement(element))
+        MarkupAccumulator::appendEndTag(element);
 }
 
 PageSerializer::PageSerializer(Vector<SerializedResource>* resources)