Add SwapMetricsObserverMac

content/browser/memory/swap_metrics_observer_mac.h

+// Copyright 2017 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 CONTENT_BROWSER_MEMORY_SWAP_METRICS_OBSERVER_MAC_H_
+#define CONTENT_BROWSER_MEMORY_SWAP_METRICS_OBSERVER_MAC_H_
+
+#include "content/browser/memory/swap_metrics_observer.h"
+
+#include "base/mac/scoped_mach_port.h"
+
+namespace content {
+
+class SwapMetricsObserverMac : public SwapMetricsObserver {
+ public:
+  SwapMetricsObserverMac();
+  ~SwapMetricsObserverMac() override;
+
+ protected:
+  void UpdateMetricsInternal(base::TimeDelta interval) override;
+
+ private:
+  base::mac::ScopedMachSendRight host_;
+
+  uint64_t last_swapins_ = 0;
+  uint64_t last_swapouts_ = 0;
+  uint64_t last_decompressions_ = 0;
+  uint64_t last_compressions_ = 0;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_MEMORY_SWAP_METRICS_OBSERVER_MAC_H_