Make iterator for Element's attributes more lightweight

Source/core/editing/MarkupAccumulator.cpp

Index: Source/core/editing/MarkupAccumulator.cpp
diff --git a/Source/core/editing/MarkupAccumulator.cpp b/Source/core/editing/MarkupAccumulator.cpp
index 09c096bedee36f48d424f71843308dd8df835d46..c17fe56b7b1c2397fe5995b7d7e9fa6660cadf74 100644
--- a/Source/core/editing/MarkupAccumulator.cpp
+++ b/Source/core/editing/MarkupAccumulator.cpp
@@ -386,10 +386,10 @@ void MarkupAccumulator::appendElement(StringBuilder& result, Element& element, N
     appendOpenTag(result, element, namespaces);
 
     if (element.hasAttributes()) {
-        AttributeIteratorAccessor attributes = element.attributesIterator();
-        AttributeConstIterator end = attributes.end();
-        for (AttributeConstIterator it = attributes.begin(); it != end; ++it)
-            appendAttribute(result, element, **it, namespaces);
+        AttributeCollection attributes = element.attributes();
+        AttributeCollection::const_iterator end = attributes.end();
+        for (AttributeCollection::const_iterator it = attributes.begin(); it != end; ++it)
+            appendAttribute(result, element, *it, namespaces);
     }
 
     // Give an opportunity to subclasses to add their own attributes.