diff -r 000000000000 -r 6474c204b198 layout/style/CSSValue.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/style/CSSValue.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,47 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* 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/. */
+
+/* DOM object representing values in DOM computed style */
+
+#ifndef mozilla_dom_CSSValue_h_
+#define mozilla_dom_CSSValue_h_
+
+#include "nsWrapperCache.h"
+
+#include "mozilla/ErrorResult.h"
+#include "nsString.h"
+
+class nsIDOMCSSValue;
+class nsROCSSPrimitiveValue;
+
+namespace mozilla {
+namespace dom {
+
+/**
+ * CSSValue - a DOM object representing values in DOM computed style.
+ */
+class CSSValue : public nsISupports,
+                 public nsWrapperCache
+{
+public:
+  // CSSValue
+  virtual void GetCssText(nsString& aText, mozilla::ErrorResult& aRv) = 0;
+  virtual void SetCssText(const nsAString& aText, mozilla::ErrorResult& aRv) = 0;
+  virtual uint16_t CssValueType() const = 0;
+
+  // Downcasting
+
+  /**
+   * Return this as a nsROCSSPrimitiveValue* if its a primitive value, and null
+   * otherwise.
+   */
+  nsROCSSPrimitiveValue *AsPrimitiveValue();
+};
+
+}
+}
+
+#endif