components/metrics: Add runtime memory leak detector

components/metrics/leak_detector/leak_detector.h

+// Copyright (c) 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_METRICS_LEAK_DETECTOR_LEAK_DETECTOR_H_
+#define COMPONENTS_METRICS_LEAK_DETECTOR_LEAK_DETECTOR_H_
+
+#include <stdint.h>
+
+namespace leak_detector {
+
+class LeakDetector {
+ public:
+  // Singleton management functions.

[jar (doing other things), 2015/08/21 02:48:42]

nit: This sure looks like a namespace, rather than a class.  Why is a class
used?

[Simon Que, 2015/08/21 05:44:05]

I haven't seen many modules in Chrome that weren't a class, but if making it a
namespace is fine, I'll make it a namespace.

[Simon Que, 2015/08/23 23:30:53]

Done.

+  static void Initialize();
+  static void Shutdown();
+  static bool IsInitialized();
+};
+
+}  // namespace leak_detector
+
+#endif  // COMPONENTS_METRICS_LEAK_DETECTOR_LEAK_DETECTOR_H_