[iOS] Upstream some stability code

ios/chrome/browser/metrics/ios_stability_metrics_provider_unittest.mm

+// Copyright 2015 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 "ios/chrome/browser/metrics/ios_stability_metrics_provider.h"
+
+#include "base/bind.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/prefs/testing_pref_service.h"
+#include "base/test/histogram_tester.h"
+#include "components/metrics/metrics_pref_names.h"
+#include "components/metrics/metrics_service.h"
+#include "components/metrics/metrics_state_manager.h"
+#include "components/metrics/test_metrics_service_client.h"
+#include "testing/gtest/include/gtest/gtest-param-test.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+bool IsMetricsReportingEnabled() {
+  return false;
+}
+
+}  // namespace
+
+// An IOSStabilityMetricsProvider that returns fake values for the last session
+// environment query methods.
+class IOSStabilityMetricsProviderForTesting
+    : public IOSStabilityMetricsProvider {
+ public:
+  explicit IOSStabilityMetricsProviderForTesting(
+      metrics::MetricsService* metrics_service)
+      : IOSStabilityMetricsProvider(metrics_service) {}
+
+  void SetIsFirstLaunchAfterUpgrade(bool value) {
+    is_first_launch_after_upgrade_ = value;
+  }
+  void SetHasCrashLogs(bool value) { has_crash_logs_ = value; }
+  void SetHasUploadedCrashReportsInBackground(bool value) {
+    has_uploaded_crash_reports_in_background_ = value;
+  }
+  void SetReceivedMemoryWarningBeforeLastShutdown(bool value) {
+    received_memory_warning_before_last_shutdown_ = value;
+  }
+
+ protected:
+  // IOSStabilityMetricsProvider:
+  bool IsFirstLaunchAfterUpgrade() override {
+    return is_first_launch_after_upgrade_;
+  }
+  bool HasCrashLogs() override { return has_crash_logs_; }
+  bool HasUploadedCrashReportsInBackground() override {
+    return has_uploaded_crash_reports_in_background_;
+  }
+  bool ReceivedMemoryWarningBeforeLastShutdown() override {
+    return received_memory_warning_before_last_shutdown_;
+  }
+
+ private:
+  bool is_first_launch_after_upgrade_;
+  bool was_last_shutdown_clean_;
+  bool has_crash_logs_;
+  bool has_uploaded_crash_reports_in_background_;
+  bool received_memory_warning_before_last_shutdown_;
+
+  DISALLOW_COPY_AND_ASSIGN(IOSStabilityMetricsProviderForTesting);
+};
+
+class IOSStabilityMetricsProviderTest : public testing::TestWithParam<int> {
+ public:
+  IOSStabilityMetricsProviderTest() {
+    metrics::MetricsService::RegisterPrefs(local_state_.registry());
+  }
+
+ protected:
+  TestingPrefServiceSimple local_state_;
+  metrics::TestMetricsServiceClient metrics_client_;
+  scoped_ptr<metrics::MetricsStateManager> metrics_state_;
+  scoped_ptr<metrics::MetricsService> metrics_service_;
+  scoped_ptr<IOSStabilityMetricsProviderForTesting> metrics_provider_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(IOSStabilityMetricsProviderTest);
+};
+
+// Verifies that a sample is recorded in the correct bucket of the shutdown type
+// histogram when ProvideStabilityMetrics is invoked.
+//
+// This parameterized test receives a parameter in the range [0, 32), which is
+// used to generate values for five booleans based on the binary
+// representation of the parameter. The bits are assigned as follows (from
+// least significant to most significant):
+//  - received memory warning;
+//  - crash log present;
+//  - uploaded crash reports in background;
+//  - last shutdown was clean;
+//  - first launch after upgrade.
+TEST_P(IOSStabilityMetricsProviderTest, ProvideStabilityMetrics) {
+  const bool received_memory_warning = GetParam() % 2;
+  const bool has_crash_logs = (GetParam() >> 1) % 2;
+  const bool has_uploaded_crash_reports_in_background = (GetParam() >> 2) % 2;
+  const bool was_last_shutdown_clean = (GetParam() >> 3) % 2;
+  const bool is_first_launch_after_upgrade = (GetParam() >> 4) % 2;
+
+  // Expected bucket for each possible value of GetParam().
+  const MobileSessionShutdownType expected_buckets[] = {
+      SHUTDOWN_IN_FOREGROUND_NO_CRASH_LOG_NO_MEMORY_WARNING,
+      SHUTDOWN_IN_FOREGROUND_NO_CRASH_LOG_WITH_MEMORY_WARNING,
+      SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_NO_MEMORY_WARNING,
+      SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_WITH_MEMORY_WARNING,
+      SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_NO_MEMORY_WARNING,
+      SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_WITH_MEMORY_WARNING,
+      SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_NO_MEMORY_WARNING,
+      SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_WITH_MEMORY_WARNING,
+      // If wasLastShutdownClean is true, the memory warning and crash log don't
+      // matter.
+      SHUTDOWN_IN_BACKGROUND,
+      SHUTDOWN_IN_BACKGROUND,
+      SHUTDOWN_IN_BACKGROUND,
+      SHUTDOWN_IN_BACKGROUND,
+      SHUTDOWN_IN_BACKGROUND,
+      SHUTDOWN_IN_BACKGROUND,
+      SHUTDOWN_IN_BACKGROUND,
+      SHUTDOWN_IN_BACKGROUND,
+      // If firstLaunchAfterUpgrade is true, the other flags don't matter.
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+      FIRST_LAUNCH_AFTER_UPGRADE,
+  };
+
+  // Setup the MetricsService.
+  local_state_.SetBoolean(metrics::prefs::kStabilityExitedCleanly,
+                          was_last_shutdown_clean);
+  metrics_state_ = metrics::MetricsStateManager::Create(
+      &local_state_, base::Bind(&IsMetricsReportingEnabled),
+      metrics::MetricsStateManager::StoreClientInfoCallback(),
+      metrics::MetricsStateManager::LoadClientInfoCallback());
+  metrics_service_.reset(new metrics::MetricsService(
+      metrics_state_.get(), &metrics_client_, &local_state_));
+
+  // Create the metrics provider to test.
+  metrics_provider_.reset(
+      new IOSStabilityMetricsProviderForTesting(metrics_service_.get()));
+
+  // Setup the metrics provider for the current test.
+  metrics_provider_->SetIsFirstLaunchAfterUpgrade(
+      is_first_launch_after_upgrade);
+  metrics_provider_->SetReceivedMemoryWarningBeforeLastShutdown(
+      received_memory_warning);
+  metrics_provider_->SetHasCrashLogs(has_crash_logs);
+  metrics_provider_->SetHasUploadedCrashReportsInBackground(
+      has_uploaded_crash_reports_in_background);
+
+  // Create a histogram tester for verifying samples written to the shutdown
+  // type histogram.
+  base::HistogramTester histogram_tester;
+
+  // Now call the method under test and verify exactly one sample is written to
+  // the expected bucket.
+  metrics_provider_->ProvideInitialStabilityMetrics(nullptr);
+  histogram_tester.ExpectUniqueSample("Stability.MobileSessionShutdownType",
+                                      expected_buckets[GetParam()], 1);
+}
+
+INSTANTIATE_TEST_CASE_P(/* No InstantiationName */,
+                        IOSStabilityMetricsProviderTest,
+                        testing::Range(0, 32));