diff -r 000000000000 -r 6474c204b198 js/xpconnect/src/XPCJSMemoryReporter.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/xpconnect/src/XPCJSMemoryReporter.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim: set ts=8 sts=4 et sw=4 tw=99: */
+/* 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 XPCJSMemoryReporter_h
+#define XPCJSMemoryReporter_h
+
+class nsISupports;
+class nsIMemoryReporterCallback;
+
+namespace xpc {
+
+// The key is the window ID.
+typedef nsDataHashtable<nsUint64HashKey, nsCString> WindowPaths;
+
+// This is very nearly an instance of nsIMemoryReporter, but it's not,
+// because it's invoked by nsWindowMemoryReporter in order to get |windowPaths|
+// in CollectReports.
+class JSReporter
+{
+public:
+    static nsresult CollectReports(WindowPaths *windowPaths,
+                                   WindowPaths *topWindowPaths,
+                                   nsIMemoryReporterCallback *cb,
+                                   nsISupports *closure);
+};
+
+}
+
+#endif