diff -r 000000000000 -r 6474c204b198 parser/html/nsHtml5AtomTable.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parser/html/nsHtml5AtomTable.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,56 @@
+/* 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/. */
+
+#include "nsHtml5AtomTable.h"
+#include "nsHtml5Atom.h"
+#include "nsThreadUtils.h"
+
+nsHtml5AtomEntry::nsHtml5AtomEntry(KeyTypePointer aStr)
+  : nsStringHashKey(aStr)
+  , mAtom(new nsHtml5Atom(*aStr))
+{
+}
+
+nsHtml5AtomEntry::nsHtml5AtomEntry(const nsHtml5AtomEntry& aOther)
+  : nsStringHashKey(aOther)
+  , mAtom(nullptr)
+{
+  NS_NOTREACHED("nsHtml5AtomTable is broken and tried to copy an entry");
+}
+
+nsHtml5AtomEntry::~nsHtml5AtomEntry()
+{
+}
+
+nsHtml5AtomTable::nsHtml5AtomTable()
+{
+#ifdef DEBUG
+  NS_GetMainThread(getter_AddRefs(mPermittedLookupThread));
+#endif
+}
+
+nsHtml5AtomTable::~nsHtml5AtomTable()
+{
+}
+
+nsIAtom*
+nsHtml5AtomTable::GetAtom(const nsAString& aKey)
+{
+#ifdef DEBUG
+  {
+    nsCOMPtr<nsIThread> currentThread;
+    NS_GetCurrentThread(getter_AddRefs(currentThread));
+    NS_ASSERTION(mPermittedLookupThread == currentThread, "Wrong thread!");
+  }
+#endif
+  nsIAtom* atom = NS_GetStaticAtom(aKey);
+  if (atom) {
+    return atom;
+  }
+  nsHtml5AtomEntry* entry = mTable.PutEntry(aKey);
+  if (!entry) {
+    return nullptr;
+  }
+  return entry->GetAtom();
+}