diff -r 000000000000 -r 6474c204b198 layout/style/nsHTMLCSSStyleSheet.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/style/nsHTMLCSSStyleSheet.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,59 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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/. */
+
+/*
+ * style sheet and style rule processor representing style attributes
+ */
+
+#ifndef nsHTMLCSSStyleSheet_h_
+#define nsHTMLCSSStyleSheet_h_
+
+#include "mozilla/Attributes.h"
+#include "mozilla/MemoryReporting.h"
+
+#include "nsDataHashtable.h"
+#include "nsIStyleRuleProcessor.h"
+
+struct MiscContainer;
+
+class nsHTMLCSSStyleSheet MOZ_FINAL : public nsIStyleRuleProcessor
+{
+public:
+  nsHTMLCSSStyleSheet();
+  ~nsHTMLCSSStyleSheet();
+
+  NS_DECL_ISUPPORTS
+
+  // nsIStyleRuleProcessor
+  virtual void RulesMatching(ElementRuleProcessorData* aData) MOZ_OVERRIDE;
+  virtual void RulesMatching(PseudoElementRuleProcessorData* aData) MOZ_OVERRIDE;
+  virtual void RulesMatching(AnonBoxRuleProcessorData* aData) MOZ_OVERRIDE;
+#ifdef MOZ_XUL
+  virtual void RulesMatching(XULTreeRuleProcessorData* aData) MOZ_OVERRIDE;
+#endif
+  virtual nsRestyleHint HasStateDependentStyle(StateRuleProcessorData* aData) MOZ_OVERRIDE;
+  virtual nsRestyleHint HasStateDependentStyle(PseudoElementStateRuleProcessorData* aData) MOZ_OVERRIDE;
+  virtual bool HasDocumentStateDependentStyle(StateRuleProcessorData* aData) MOZ_OVERRIDE;
+  virtual nsRestyleHint
+    HasAttributeDependentStyle(AttributeRuleProcessorData* aData) MOZ_OVERRIDE;
+  virtual bool MediumFeaturesChanged(nsPresContext* aPresContext) MOZ_OVERRIDE;
+  virtual size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf)
+    const MOZ_MUST_OVERRIDE MOZ_OVERRIDE;
+  virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf)
+    const MOZ_MUST_OVERRIDE MOZ_OVERRIDE;
+
+  void CacheStyleAttr(const nsAString& aSerialized, MiscContainer* aValue);
+  void EvictStyleAttr(const nsAString& aSerialized, MiscContainer* aValue);
+  MiscContainer* LookupStyleAttr(const nsAString& aSerialized);
+
+private: 
+  nsHTMLCSSStyleSheet(const nsHTMLCSSStyleSheet& aCopy) MOZ_DELETE;
+  nsHTMLCSSStyleSheet& operator=(const nsHTMLCSSStyleSheet& aCopy) MOZ_DELETE;
+
+protected:
+  nsDataHashtable<nsStringHashKey, MiscContainer*> mCachedStyleAttrs;
+};
+
+#endif /* !defined(nsHTMLCSSStyleSheet_h_) */