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

chrome/browser/memory/memory_kills_histogram.h

Index: chrome/browser/memory/memory_kills_histogram.h
diff --git a/components/arc/metrics/oom_kills_histogram.h b/chrome/browser/memory/memory_kills_histogram.h
similarity index 63%
rename from components/arc/metrics/oom_kills_histogram.h
rename to chrome/browser/memory/memory_kills_histogram.h
index 2a9bf562fa4c8aab5d50189259ad759a4cc41302..07c8b4c68976111417a79f1830cd183ed004e23a 100644
--- a/components/arc/metrics/oom_kills_histogram.h
+++ b/chrome/browser/memory/memory_kills_histogram.h
@@ -2,22 +2,22 @@
 // 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_
+#ifndef CHROME_BROWSER_MEMORY_MEMORY_KILLS_HISTOGRAM_H_
+#define CHROME_BROWSER_MEMORY_MEMORY_KILLS_HISTOGRAM_H_
 
 #include "base/metrics/histogram.h"

[hidehiko, 2016/11/25 10:13:21]

#include "base/time/time.h", too?

[cylee1, 2016/11/29 20:28:40]

Done.

 
-namespace arc {
+namespace memory {
 
-const int kMaxOomMemoryKillTimeDeltaSecs = 30;
+const int kMaxMemoryKillTimeDeltaSecs = 30;

[hidehiko, 2016/11/25 10:13:21]

base::TimeDelta supports constexpr. So,

constexpr base::TimeDelta kMaxMemoryKillTimeDelta =
    base::TimeDelta::FromSeconds(30);

seems better?

[cylee1, 2016/11/29 20:28:40]

Done.

 
-}  // namespace arc
+}  // namespace memory
 
 // 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)
+      base::TimeDelta::FromSeconds(::memory::kMaxMemoryKillTimeDeltaSecs), 50)
 
-#endif  // COMPONENTS_ARC_METRICS_OOM_KILLS_HISTOGRAM_H_
+#endif  // CHROME_BROWSER_MEMORY_MEMORY_KILLS_HISTOGRAM_H_