ArcLowMemoryKillerMonitor:

chrome/browser/chromeos/arc/arc_low_memory_killer_monitor.h

+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_ARC_ARC_LOW_MEMORY_KILLER_MONITOR_H_
+#define CHROME_BROWSER_CHROMEOS_ARC_ARC_LOW_MEMORY_KILLER_MONITOR_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/sequenced_worker_pool.h"
+
+namespace arc {
+
+// Trace lowmemorykiller events and report to UMA.
+//
+// If kernel lowmemorykiller is enabled, it would kill processes automatically
+// on memory pressure. ArcLowMemoryKillerMonitor listens on lowmemorykiller log
+// from kernel space and reports to UMA.
+//
+// Note: There should be only one ArcLowMemoryKillerMonitor instance during the
+// power cycle of a Chrome OS device, otherwise an lowmemorykiller event would
+// be reported twice since it reads in the entire kernel log from head.
+// On Chrome OS, it should live within a main browser thread.
+class ArcLowMemoryKillerMonitor {
+ public:
+  ArcLowMemoryKillerMonitor();
+  ~ArcLowMemoryKillerMonitor();
+
+  void Start();
+  void Stop();
+
+ private:
+  // Keep a reference to worker_pool_ in case |this| is deleted in
+  // shutdown process while this thread returns from a blocking read.
+  void Run(scoped_refptr<base::SequencedWorkerPool> worker_pool);

[Yusuke Sato, 2016/03/15 16:59:45]

Can this function be static now? If so, I think you can remove line 10 and
40-42.

[cylee1, 2016/03/15 18:26:57]

True. Thanks !

+
+  scoped_refptr<base::SequencedWorkerPool> worker_pool_;
+
+  // Always keep this the last member of this class to make sure it's the
+  // first thing to be destructed.
+  base::WeakPtrFactory<ArcLowMemoryKillerMonitor> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcLowMemoryKillerMonitor);
+};
+
+}  // namespace arc
+
+#endif  // CHROME_BROWSER_CHROMEOS_ARC_ARC_LOW_MEMORY_KILLER_MONITOR_H_"