metrics: Add leak detector controller in Chrome OS metrics system

components/metrics/leak_detector/leak_detector.cc

+// Copyright 2016 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.
+
+#include "components/metrics/leak_detector/leak_detector.h"
+
+#include <algorithm>
+
+namespace metrics {
+
+LeakDetector::LeakReport::LeakReport() {}
+
+LeakDetector::LeakReport::~LeakReport() {}
+
+LeakDetector::LeakDetector(float sampling_rate,
+                           int max_stack_depth,
+                           uint64_t analysis_interval_bytes,
+                           int size_suspicion_threshold,
+                           int call_stack_suspicion_threshold) {}
+
+LeakDetector::LeakDetector() : LeakDetector(1.0f, 4, 32 * 1024 * 1024, 4, 4) {}
+
+LeakDetector::~LeakDetector() {}
+
+void LeakDetector::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void LeakDetector::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void LeakDetector::NotifyObservers(const std::vector<LeakReport>& reports) {
+  for (const LeakReport& report : reports) {
+    FOR_EACH_OBSERVER(Observer, observers_, OnLeakFound(report));
+  }
+}
+
+}  // namespace metrics