diff -r 000000000000 -r 6474c204b198 parser/html/nsHtml5DependentUTF16Buffer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parser/html/nsHtml5DependentUTF16Buffer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,31 @@
+/* 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/. */
+
+#ifndef nsHtml5DependentUTF16Buffer_h
+#define nsHtml5DependentUTF16Buffer_h
+
+#include "nscore.h"
+#include "nsHtml5OwningUTF16Buffer.h"
+
+class MOZ_STACK_CLASS nsHtml5DependentUTF16Buffer : public nsHtml5UTF16Buffer
+{
+  public:
+    /**
+     * Wraps a string without taking ownership of the buffer. aToWrap MUST NOT
+     * go away or be shortened while nsHtml5DependentUTF16Buffer is in use.
+     */
+    nsHtml5DependentUTF16Buffer(const nsAString& aToWrap);
+
+    ~nsHtml5DependentUTF16Buffer();
+
+    /**
+     * Copies the currently unconsumed part of this buffer into a new
+     * heap-allocated nsHtml5OwningUTF16Buffer. The new object is allocated
+     * with a fallible allocator. If the allocation fails, nullptr is returned.
+     * @return heap-allocated copy or nullptr if memory allocation failed
+     */
+    already_AddRefed<nsHtml5OwningUTF16Buffer> FalliblyCopyAsOwningBuffer();
+};
+
+#endif // nsHtml5DependentUTF16Buffer_h