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

chrome/browser/memory/memory_kills_monitor_unittest.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 "chrome/browser/memory/memory_kills_monitor.h"
+
+#include "base/macros.h"
+#include "base/metrics/histogram_base.h"
+#include "base/metrics/histogram_samples.h"
+#include "base/metrics/statistics_recorder.h"
+#include "base/time/time.h"
+#include "chrome/browser/memory/memory_kills_histogram.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace memory {
+
+using MemoryKillsMonitorTest = testing::Test;
+
+TEST_F(MemoryKillsMonitorTest, LogLowMemoryKill) {
+  MemoryKillsMonitor::LogLowMemoryKill("APP", 123);
+  MemoryKillsMonitor::LogLowMemoryKill("APP", 100);
+  MemoryKillsMonitor::LogLowMemoryKill("TAB", 10000);
+
+  auto histogram_count =
+      base::StatisticsRecorder::FindHistogram("Arc.LowMemoryKiller.Count");
+  ASSERT_TRUE(histogram_count);
+  auto count_samples = histogram_count->SnapshotSamples();
+  EXPECT_EQ(3, count_samples->TotalCount());
+  EXPECT_EQ(1, count_samples->GetCount(1));
+  EXPECT_EQ(1, count_samples->GetCount(2));
+  EXPECT_EQ(1, count_samples->GetCount(3));
+
+  auto histogram_freed_size =
+      base::StatisticsRecorder::FindHistogram("Arc.LowMemoryKiller.FreedSize");
+  ASSERT_TRUE(histogram_freed_size);
+  auto freed_size_samples = histogram_freed_size->SnapshotSamples();
+  EXPECT_EQ(3, freed_size_samples->TotalCount());
+  // 123 and 100 are in the same bucket.
+  EXPECT_EQ(2, freed_size_samples->GetCount(123));
+  EXPECT_EQ(2, freed_size_samples->GetCount(100));
+  EXPECT_EQ(1, freed_size_samples->GetCount(10000));
+
+  auto histogram_time_delta =
+      base::StatisticsRecorder::FindHistogram("Arc.LowMemoryKiller.TimeDelta");
+  ASSERT_TRUE(histogram_time_delta);
+  auto time_delta_samples = histogram_time_delta->SnapshotSamples();
+  EXPECT_EQ(3, time_delta_samples->TotalCount());
+  // First time delta is set to kMaxMemoryKillTimeDelta.
+  EXPECT_EQ(1, time_delta_samples->GetCount(
+      kMaxMemoryKillTimeDelta.InMilliseconds()));
+  // Time delta for the other 2 events depends on Now() so we skip testing it
+  // here.
+}
+
+TEST_F(MemoryKillsMonitorTest, TryMatchOomKillLine) {
+  const char* sample_lines[] = {
+      "3,3429,812967386,-;Out of memory: Kill process 8291 (handle-watcher-) "
+      "score 674 or sacrifice child",
+      "3,3431,812981331,-;Out of memory: Kill process 8271 (.gms.persistent) "
+      "score 652 or sacrifice child",
+      "3,3433,812993014,-;Out of memory: Kill process 9210 (lowpool[11]) "
+      "score 653 or sacrifice child"
+  };
+
+  for (unsigned long i = 0; i < arraysize(sample_lines); ++i) {
+    MemoryKillsMonitor::TryMatchOomKillLine(sample_lines[i]);
+  }
+
+  auto histogram_count =
+      base::StatisticsRecorder::FindHistogram("Arc.OOMKills.Count");
+  ASSERT_TRUE(histogram_count);
+  auto count_samples = histogram_count->SnapshotSamples();
+  EXPECT_EQ(3, count_samples->TotalCount());
+  EXPECT_EQ(1, count_samples->GetCount(1));
+  EXPECT_EQ(1, count_samples->GetCount(2));
+  EXPECT_EQ(1, count_samples->GetCount(3));
+
+  auto histogram_score =
+      base::StatisticsRecorder::FindHistogram("Arc.OOMKills.Score");
+  ASSERT_TRUE(histogram_score);
+  auto score_samples = histogram_score->SnapshotSamples();
+  EXPECT_EQ(3, score_samples->TotalCount());
+  EXPECT_EQ(1, score_samples->GetCount(674));
+  EXPECT_EQ(1, score_samples->GetCount(652));
+  EXPECT_EQ(1, score_samples->GetCount(653));
+
+  auto histogram_time_delta =
+      base::StatisticsRecorder::FindHistogram("Arc.OOMKills.TimeDelta");
+  ASSERT_TRUE(histogram_time_delta);
+  auto time_delta_samples = histogram_time_delta->SnapshotSamples();
+  EXPECT_EQ(3, time_delta_samples->TotalCount());
+  // First time delta is set to kMaxMemoryKillTimeDelta.
+  EXPECT_EQ(1, time_delta_samples->GetCount(
+      kMaxMemoryKillTimeDelta.InMilliseconds()));
+  EXPECT_EQ(1, time_delta_samples->GetCount(11));
+  EXPECT_EQ(1, time_delta_samples->GetCount(13));
+}
+
+}  // namespace memory