Drop const_iterator for AttributeCollection

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 3ef2a673759a14eb35a878d1bfc5d07eac3ee249..eb04ba1be60968466ccf132422c8be539595ef15 100644
--- a/Source/core/page/PageSerializer.cpp
+++ b/Source/core/page/PageSerializer.cpp
@@ -77,8 +77,8 @@ static bool isCharsetSpecifyingNode(const Node& node)
     const HTMLMetaElement& element = toHTMLMetaElement(node);
     HTMLAttributeList attributeList;
     AttributeCollection attributes = element.attributes();
-    AttributeCollection::const_iterator end = attributes.end();
-    for (AttributeCollection::const_iterator it = attributes.begin(); it != end; ++it) {
+    AttributeCollection::iterator end = attributes.end();
+    for (AttributeCollection::iterator it = attributes.begin(); it != end; ++it) {
         // FIXME: We should deal appropriately with the attribute if they have a namespace.
         attributeList.append(std::make_pair(it->name().localName(), it->value().string()));
     }