diff -r 000000000000 -r 6474c204b198 dom/bindings/ToJSValue.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/bindings/ToJSValue.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* vim: set ts=2 sw=2 et tw=79: */
+/* 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 "mozilla/dom/ToJSValue.h"
+#include "mozilla/dom/DOMException.h"
+#include "mozilla/dom/Exceptions.h"
+#include "nsAString.h"
+#include "nsContentUtils.h"
+#include "nsStringBuffer.h"
+#include "xpcpublic.h"
+
+namespace mozilla {
+namespace dom {
+
+bool
+ToJSValue(JSContext* aCx, const nsAString& aArgument,
+          JS::MutableHandle<JS::Value> aValue)
+{
+  // Make sure we're called in a compartment
+  MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+// XXXkhuey I'd love to use xpc::NonVoidStringToJsval here, but it requires
+  // a non-const nsAString for silly reasons.
+  nsStringBuffer* sharedBuffer;
+  if (!XPCStringConvert::ReadableToJSVal(aCx, aArgument, &sharedBuffer,
+                                         aValue)) {
+    return false;
+  }
+
+  if (sharedBuffer) {
+    NS_ADDREF(sharedBuffer);
+  }
+
+  return true;
+}
+
+
+namespace tojsvalue_detail {
+
+bool
+ISupportsToJSValue(JSContext* aCx,
+                   nsISupports* aArgument,
+                   JS::MutableHandle<JS::Value> aValue)
+{
+  nsresult rv = nsContentUtils::WrapNative(aCx, aArgument, aValue);
+  return NS_SUCCEEDED(rv);
+}
+
+} // namespace tojsvalue_detail
+
+bool
+ToJSValue(JSContext* aCx,
+          nsresult aArgument,
+          JS::MutableHandle<JS::Value> aValue)
+{
+  nsRefPtr<Exception> exception = CreateException(aCx, aArgument);
+  return ToJSValue(aCx, exception, aValue);
+}
+
+} // namespace dom
+} // namespace mozilla