Revert of Add support for single sample metrics.

base/metrics/single_sample_metrics_unittest.cc

Index: base/metrics/single_sample_metrics_unittest.cc
diff --git a/base/metrics/single_sample_metrics_unittest.cc b/base/metrics/single_sample_metrics_unittest.cc
deleted file mode 100644
index e3c1cf0e2bebe9380908bbb42c7b2830a05f1c23..0000000000000000000000000000000000000000
--- a/base/metrics/single_sample_metrics_unittest.cc
+++ /dev/null
@@ -1,121 +0,0 @@
-// 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.
-
-#include "base/metrics/single_sample_metrics.h"
-
-#include "base/memory/ptr_util.h"
-#include "base/test/gtest_util.h"
-#include "base/test/histogram_tester.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace base {
-
-namespace {
-
-const HistogramBase::Sample kMin = 1;
-const HistogramBase::Sample kMax = 10;
-const uint32_t kBucketCount = 10;
-const char kMetricName[] = "Single.Sample.Metric";
-
-class SingleSampleMetricsTest : public testing::Test {
- public:
-  SingleSampleMetricsTest() {}
-
-  ~SingleSampleMetricsTest() override {
-    // Ensure we cleanup after ourselves.
-    SingleSampleMetricsFactory::DeleteFactoryForTesting();
-  }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(SingleSampleMetricsTest);
-};
-
-}  // namespace
-
-TEST_F(SingleSampleMetricsTest, DefaultFactoryGetSet) {
-  SingleSampleMetricsFactory* factory = SingleSampleMetricsFactory::Get();
-  ASSERT_TRUE(factory);
-
-  // Same factory should be returned evermore.
-  EXPECT_EQ(factory, SingleSampleMetricsFactory::Get());
-
-  // Setting a factory after the default has been instantiated should fail.
-  EXPECT_DCHECK_DEATH(SingleSampleMetricsFactory::SetFactory(
-      WrapUnique<SingleSampleMetricsFactory>(nullptr)));
-}
-
-TEST_F(SingleSampleMetricsTest, CustomFactoryGetSet) {
-  SingleSampleMetricsFactory* factory = new DefaultSingleSampleMetricsFactory();
-  SingleSampleMetricsFactory::SetFactory(WrapUnique(factory));
-  EXPECT_EQ(factory, SingleSampleMetricsFactory::Get());
-}
-
-TEST_F(SingleSampleMetricsTest, DefaultSingleSampleMetricNoValue) {
-  SingleSampleMetricsFactory* factory = SingleSampleMetricsFactory::Get();
-
-  HistogramTester tester;
-  std::unique_ptr<SingleSampleMetric> metric =
-      factory->CreateCustomCountsMetric(kMetricName, kMin, kMax, kBucketCount);
-  metric.reset();
-
-  // Verify that no sample is recorded if SetSample() is never called.
-  tester.ExpectTotalCount(kMetricName, 0);
-}
-
-TEST_F(SingleSampleMetricsTest, DefaultSingleSampleMetricWithValue) {
-  SingleSampleMetricsFactory* factory = SingleSampleMetricsFactory::Get();
-
-  HistogramTester tester;
-  std::unique_ptr<SingleSampleMetric> metric =
-      factory->CreateCustomCountsMetric(kMetricName, kMin, kMax, kBucketCount);
-
-  const HistogramBase::Sample kLastSample = 9;
-  metric->SetSample(1);
-  metric->SetSample(3);
-  metric->SetSample(5);
-  metric->SetSample(kLastSample);
-  metric.reset();
-
-  // Verify only the last sample sent to SetSample() is recorded.
-  tester.ExpectUniqueSample(kMetricName, kLastSample, 1);
-
-  // Verify construction implicitly by requesting a histogram with the same
-  // parameters; this test relies on the fact that histogram objects are unique
-  // per name. Different parameters will result in a nullptr being returned.
-  EXPECT_FALSE(
-      Histogram::FactoryGet(kMetricName, 1, 3, 3, HistogramBase::kNoFlags));
-  EXPECT_TRUE(Histogram::FactoryGet(kMetricName, kMin, kMax, kBucketCount,
-                                    HistogramBase::kUmaTargetedHistogramFlag));
-}
-
-TEST_F(SingleSampleMetricsTest, MultipleMetricsAreDistinct) {
-  SingleSampleMetricsFactory* factory = SingleSampleMetricsFactory::Get();
-
-  HistogramTester tester;
-  std::unique_ptr<SingleSampleMetric> metric =
-      factory->CreateCustomCountsMetric(kMetricName, kMin, kMax, kBucketCount);
-  std::unique_ptr<SingleSampleMetric> metric2 =
-      factory->CreateCustomCountsMetric(kMetricName, kMin, kMax, kBucketCount);
-  const char kMetricName2[] = "Single.Sample.Metric.2";
-  std::unique_ptr<SingleSampleMetric> metric3 =
-      factory->CreateCustomCountsMetric(kMetricName2, kMin, kMax, kBucketCount);
-
-  const HistogramBase::Sample kSample1 = 5;
-  metric->SetSample(kSample1);
-  metric2->SetSample(kSample1);
-
-  const HistogramBase::Sample kSample2 = 7;
-  metric3->SetSample(kSample2);
-
-  metric.reset();
-  tester.ExpectUniqueSample(kMetricName, kSample1, 1);
-
-  metric2.reset();
-  tester.ExpectUniqueSample(kMetricName, kSample1, 2);
-
-  metric3.reset();
-  tester.ExpectUniqueSample(kMetricName2, kSample2, 1);
-}
-
-}  // namespace base