Resetting metrics ids on clump detection.

chrome/browser/metrics/cloned_install_detector_unittest.cc

 // Copyright 2014 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/metrics/cloned_install_detector.h"
 
 #include "base/prefs/testing_pref_service.h"
 #include "chrome/browser/metrics/machine_id_provider.h"
+#include "chrome/browser/metrics/metrics_service.h"
 #include "chrome/common/pref_names.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace metrics {
 
 namespace {
 
 const std::string kTestRawId = "test";
 // Hashed machine id for |kTestRawId|.
 const int kTestHashedId = 2216819;
 
 }  // namespace
 
-// TODO(jwd): Change this test to test the full flow and histogram outputs. It
+// TODO(jwd): Change these test to test the full flow and histogram outputs. It
 // should also remove the need to make the test a friend of
 // ClonedInstallDetector.
 TEST(ClonedInstallDetectorTest, SaveId) {
   TestingPrefServiceSimple prefs;
   ClonedInstallDetector::RegisterPrefs(prefs.registry());
 
   scoped_ptr<ClonedInstallDetector> detector(
       new ClonedInstallDetector(MachineIdProvider::CreateInstance()));
 
   detector->SaveMachineId(&prefs, kTestRawId);
 
   EXPECT_EQ(kTestHashedId, prefs.GetInteger(prefs::kMetricsMachineId));
 }
 
+TEST(ClonedInstallDetectorTest, DetectClone) {
+  TestingPrefServiceSimple prefs;
+  ClonedInstallDetector::RegisterPrefs(prefs.registry());
+  MetricsService::RegisterPrefs(prefs.registry());
+
+  // Save a machine id that will cause a clone to be detected.
+  prefs.SetInteger(prefs::kMetricsMachineId, kTestHashedId + 1);
+
+  scoped_ptr<ClonedInstallDetector> detector(
+      new ClonedInstallDetector(MachineIdProvider::CreateInstance()));
+
+  detector->SaveMachineId(&prefs, kTestRawId);
+
+  EXPECT_TRUE(prefs.GetBoolean(prefs::kMetricsResetIds));
+}
+
 }  // namespace metrics