diff -r 000000000000 -r 6474c204b198 content/base/src/nsMappedAttributeElement.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/base/src/nsMappedAttributeElement.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,48 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set tw=80 expandtab softtabstop=2 ts=2 sw=2: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * nsMappedAttributeElement is the base for elements supporting style mapped
+ * attributes via nsMappedAttributes (HTML and MathML).
+ */
+
+#ifndef NS_MAPPEDATTRIBUTEELEMENT_H_
+#define NS_MAPPEDATTRIBUTEELEMENT_H_
+
+#include "mozilla/Attributes.h"
+#include "nsStyledElement.h"
+
+class nsMappedAttributes;
+struct nsRuleData;
+
+typedef void (*nsMapRuleToAttributesFunc)(const nsMappedAttributes* aAttributes, 
+                                          nsRuleData* aData);
+
+typedef nsStyledElement nsMappedAttributeElementBase;
+
+class nsMappedAttributeElement : public nsMappedAttributeElementBase
+{
+
+protected:
+
+  nsMappedAttributeElement(already_AddRefed<nsINodeInfo>& aNodeInfo)
+    : nsMappedAttributeElementBase(aNodeInfo)
+  {}
+
+public:
+  virtual nsMapRuleToAttributesFunc GetAttributeMappingFunction() const;
+
+  static void MapNoAttributesInto(const nsMappedAttributes* aAttributes, 
+                                  nsRuleData* aRuleData);
+
+  NS_IMETHOD WalkContentStyleRules(nsRuleWalker* aRuleWalker) MOZ_OVERRIDE;
+  virtual bool SetMappedAttribute(nsIDocument* aDocument,
+                                    nsIAtom* aName,
+                                    nsAttrValue& aValue,
+                                    nsresult* aRetval) MOZ_OVERRIDE;
+};
+
+#endif // NS_MAPPEDATTRIBUTEELEMENT_H_