diff -r 000000000000 -r 6474c204b198 xpcom/base/nsTraceRefcnt.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/base/nsTraceRefcnt.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 nsTraceRefcnt_h___
+#define nsTraceRefcnt_h___
+
+#include <stdio.h> // for FILE
+#include "nscore.h"
+
+class nsTraceRefcnt
+{
+public:
+  static void Startup();
+  static void Shutdown();
+
+  enum StatisticsType {
+    ALL_STATS,
+    NEW_STATS
+  };
+
+  static nsresult DumpStatistics(StatisticsType type = ALL_STATS,
+                                        FILE* out = 0);
+
+  static void ResetStatistics(void);
+
+  static void DemangleSymbol(const char * aSymbol,
+                                    char * aBuffer,
+                                    int aBufLen);
+
+  static void WalkTheStack(FILE* aStream);
+  /**
+   * Tell nsTraceRefcnt whether refcounting, allocation, and destruction
+   * activity is legal.  This is used to trigger assertions for any such
+   * activity that occurs because of static constructors or destructors.
+   */
+  static void SetActivityIsLegal(bool aLegal);
+};
+
+#define NS_TRACE_REFCNT_CONTRACTID "@mozilla.org/xpcom/trace-refcnt;1"
+#define NS_TRACE_REFCNT_CID                          \
+{ /* e3e7511e-a395-4924-94b1-d527861cded4 */         \
+    0xe3e7511e,                                      \
+    0xa395,                                          \
+    0x4924,                                          \
+    {0x94, 0xb1, 0xd5, 0x27, 0x86, 0x1c, 0xde, 0xd4} \
+}                                                    \
+
+////////////////////////////////////////////////////////////////////////////////
+// And now for that utility that you've all been asking for...
+
+extern "C" void
+NS_MeanAndStdDev(double n, double sumOfValues, double sumOfSquaredValues,
+                 double *meanResult, double *stdDevResult);
+
+////////////////////////////////////////////////////////////////////////////////
+#endif