Consolidate code monitoring low memory kills and OOM kills to MemoryKillsMonitor on ChromeOS.

components/arc/metrics/oom_kills_histogram.h

Index: components/arc/metrics/oom_kills_histogram.h
diff --git a/components/arc/metrics/oom_kills_histogram.h b/components/arc/metrics/oom_kills_histogram.h
deleted file mode 100644
index 2a9bf562fa4c8aab5d50189259ad759a4cc41302..0000000000000000000000000000000000000000
--- a/components/arc/metrics/oom_kills_histogram.h
+++ /dev/null
@@ -1,23 +0,0 @@
-// 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 COMPONENTS_ARC_METRICS_OOM_KILLS_HISTOGRAM_H_
-#define COMPONENTS_ARC_METRICS_OOM_KILLS_HISTOGRAM_H_
-
-#include "base/metrics/histogram.h"
-
-namespace arc {
-
-const int kMaxOomMemoryKillTimeDeltaSecs = 30;
-
-}  // namespace arc
-
-// Use this macro to report elapsed time since last OOM kill event.
-// Must be a macro as the underlying HISTOGRAM macro creates static variables.
-#define UMA_HISTOGRAM_OOM_KILL_TIME_INTERVAL(name, sample)  \
-  UMA_HISTOGRAM_CUSTOM_TIMES(                               \
-      name, sample, base::TimeDelta::FromMilliseconds(1),   \
-      base::TimeDelta::FromSeconds(::arc::kMaxOomMemoryKillTimeDeltaSecs), 50)
-
-#endif  // COMPONENTS_ARC_METRICS_OOM_KILLS_HISTOGRAM_H_