Get rid of excessive CrosSettings::Get()->Set*() usage, mostly in tests.

The following tests were affected:

unit_tests:
AttestationPolicyObserverTest.*
CryptohomeAuthenticatorTest.*
ExtensionCacheTest.*
EPKPChallengeMachineKeyTest.DevicePolicyDisabled
EPKPChallengeUserKeyTest.DevicePolicyDisabled
HeartbeatSchedulerTest.*
NetworkConfigurationUpdaterTest.*
PlatformVerificationFlowTest.*
StatusUploaderTest.*
ShutdownPolicyHandlerTest.*
UserManagerTest.*

browser_tests:
DeviceStatusCollectorTest.*
KioskAppManagerTest.*
KioskEnterpriseTest.*
KioskTest.*
KioskUpdateTest.*

BUG=433840

Review URL: https://codereview.chromium.org/1019283004

Cr-Commit-Position: refs/heads/master@{#326338}

35 files changed, 573 insertions, 533 deletions

diff --git a/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc b/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
index ab182b5..a37df89 100644
--- a/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
+++ b/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
@@ -23,6 +23,7 @@
 #include "chrome/browser/chromeos/app_mode/kiosk_app_external_loader.h"
 #include "chrome/browser/chromeos/app_mode/kiosk_app_manager_observer.h"
 #include "chrome/browser/chromeos/app_mode/kiosk_external_updater.h"
+#include "chrome/browser/chromeos/ownership/owner_settings_service_chromeos.h"
 #include "chrome/browser/chromeos/ownership/owner_settings_service_chromeos_factory.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/policy/device_local_account.h"
@@ -183,20 +184,20 @@ std::string KioskAppManager::GetAutoLaunchApp() const {
   return auto_launch_app_id_;
 }
 
-void KioskAppManager::SetAutoLaunchApp(const std::string& app_id) {
+void KioskAppManager::SetAutoLaunchApp(const std::string& app_id,
+                                       OwnerSettingsServiceChromeOS* service) {
   SetAutoLoginState(AUTOLOGIN_REQUESTED);
   // Clean first, so the proper change callbacks are triggered even
   // if we are only changing AutoLoginState here.
   if (!auto_launch_app_id_.empty()) {
-    CrosSettings::Get()->SetString(kAccountsPrefDeviceLocalAccountAutoLoginId,
-                                   std::string());
+    service->SetString(kAccountsPrefDeviceLocalAccountAutoLoginId,
+                       std::string());
   }
 
-  CrosSettings::Get()->SetString(
+  service->SetString(
       kAccountsPrefDeviceLocalAccountAutoLoginId,
       app_id.empty() ? std::string() : GenerateKioskAppAccountId(app_id));
-  CrosSettings::Get()->SetInteger(
-      kAccountsPrefDeviceLocalAccountAutoLoginDelay, 0);
+  service->SetInteger(kAccountsPrefDeviceLocalAccountAutoLoginDelay, 0);
 }
 
 void KioskAppManager::SetAppWasAutoLaunchedWithZeroDelay(
@@ -332,7 +333,8 @@ bool KioskAppManager::IsAutoLaunchEnabled() const {
   return GetAutoLoginState() == AUTOLOGIN_APPROVED;
 }
 
-void KioskAppManager::AddApp(const std::string& app_id) {
+void KioskAppManager::AddApp(const std::string& app_id,
+                             OwnerSettingsServiceChromeOS* service) {
   std::vector<policy::DeviceLocalAccount> device_local_accounts =
       policy::GetDeviceLocalAccounts(CrosSettings::Get());
 
@@ -353,13 +355,14 @@ void KioskAppManager::AddApp(const std::string& app_id) {
       app_id,
       std::string()));
 
-  policy::SetDeviceLocalAccounts(CrosSettings::Get(), device_local_accounts);
+  policy::SetDeviceLocalAccounts(service, device_local_accounts);
 }
 
-void KioskAppManager::RemoveApp(const std::string& app_id) {
+void KioskAppManager::RemoveApp(const std::string& app_id,
+                                OwnerSettingsServiceChromeOS* service) {
   // Resets auto launch app if it is the removed app.
   if (auto_launch_app_id_ == app_id)
-    SetAutoLaunchApp(std::string());
+    SetAutoLaunchApp(std::string(), service);
 
   std::vector<policy::DeviceLocalAccount> device_local_accounts =
       policy::GetDeviceLocalAccounts(CrosSettings::Get());
@@ -377,7 +380,7 @@ void KioskAppManager::RemoveApp(const std::string& app_id) {
     }
   }
 
-  policy::SetDeviceLocalAccounts(CrosSettings::Get(), device_local_accounts);
+  policy::SetDeviceLocalAccounts(service, device_local_accounts);
 }
 
 void KioskAppManager::GetApps(Apps* apps) const {
diff --git a/chrome/browser/chromeos/app_mode/kiosk_app_manager.h b/chrome/browser/chromeos/app_mode/kiosk_app_manager.h
index aff5898..72d511c 100644
--- a/chrome/browser/chromeos/app_mode/kiosk_app_manager.h
+++ b/chrome/browser/chromeos/app_mode/kiosk_app_manager.h
@@ -38,6 +38,7 @@ class KioskAppData;
 class KioskAppExternalLoader;
 class KioskAppManagerObserver;
 class KioskExternalUpdater;
+class OwnerSettingsServiceChromeOS;
 
 // KioskAppManager manages cached app data.
 class KioskAppManager : public KioskAppDataDelegate,
@@ -121,7 +122,8 @@ class KioskAppManager : public KioskAppDataDelegate,
   std::string GetAutoLaunchApp() const;
 
   // Sets |app_id| as the app to auto launch at start up.
-  void SetAutoLaunchApp(const std::string& app_id);
+  void SetAutoLaunchApp(const std::string& app_id,
+                        OwnerSettingsServiceChromeOS* service);
 
   // Returns true if there is a pending auto-launch request.
   bool IsAutoLaunchRequested() const;
@@ -134,8 +136,9 @@ class KioskAppManager : public KioskAppDataDelegate,
 
   // Adds/removes a kiosk app by id. When removed, all locally cached data
   // will be removed as well.
-  void AddApp(const std::string& app_id);
-  void RemoveApp(const std::string& app_id);
+  void AddApp(const std::string& app_id, OwnerSettingsServiceChromeOS* service);
+  void RemoveApp(const std::string& app_id,
+                 OwnerSettingsServiceChromeOS* service);
 
   // Gets info of all apps that have no meta data load error.
   void GetApps(Apps* apps) const;
diff --git a/chrome/browser/chromeos/app_mode/kiosk_app_manager_browsertest.cc b/chrome/browser/chromeos/app_mode/kiosk_app_manager_browsertest.cc
index 48498b6..16f85d0 100644
--- a/chrome/browser/chromeos/app_mode/kiosk_app_manager_browsertest.cc
+++ b/chrome/browser/chromeos/app_mode/kiosk_app_manager_browsertest.cc
@@ -7,6 +7,7 @@
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/path_service.h"
 #include "base/prefs/scoped_user_pref_update.h"
@@ -15,9 +16,10 @@
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/app_mode/fake_cws.h"
 #include "chrome/browser/chromeos/app_mode/kiosk_app_manager_observer.h"
+#include "chrome/browser/chromeos/ownership/fake_owner_settings_service.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/policy/device_local_account.h"
-#include "chrome/browser/chromeos/settings/cros_settings.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
@@ -165,7 +167,7 @@ class AppDataLoadWaiter : public KioskAppManagerObserver {
 
 class KioskAppManagerTest : public InProcessBrowserTest {
  public:
-  KioskAppManagerTest() : fake_cws_(new FakeCWS()) {}
+  KioskAppManagerTest() : settings_helper_(false), fake_cws_(new FakeCWS()) {}
   ~KioskAppManagerTest() override {}
 
   // InProcessBrowserTest overrides:
@@ -195,8 +197,14 @@ class KioskAppManagerTest : public InProcessBrowserTest {
 
     // Restart the thread as the sandbox host process has already been spawned.
     embedded_test_server()->RestartThreadAndListen();
+
+    settings_helper_.ReplaceProvider(kAccountsPrefDeviceLocalAccounts);
+    owner_settings_service_ =
+        settings_helper_.CreateOwnerSettingsService(browser()->profile());
   }
 
+  void TearDownOnMainThread() override { settings_helper_.RestoreProvider(); }
+
   void SetUpInProcessBrowserTestFixture() override {
     InProcessBrowserTest::SetUpInProcessBrowserTestFixture();
 
@@ -270,8 +278,8 @@ class KioskAppManagerTest : public InProcessBrowserTest {
         kAccountsPrefDeviceLocalAccountsKeyKioskAppId,
         app_id);
     device_local_accounts.Append(entry.release());
-    CrosSettings::Get()->Set(kAccountsPrefDeviceLocalAccounts,
-                             device_local_accounts);
+    owner_settings_service_->Set(kAccountsPrefDeviceLocalAccounts,
+                                 device_local_accounts);
   }
 
   bool GetCachedCrx(const std::string& app_id,
@@ -289,7 +297,7 @@ class KioskAppManagerTest : public InProcessBrowserTest {
     fake_cws_->SetUpdateCrx(id, crx_file_name, version);
 
     AppDataLoadWaiter waiter(manager(), 3);
-    manager()->AddApp(id);
+    manager()->AddApp(id, owner_settings_service_.get());
     waiter.Wait();
     EXPECT_TRUE(waiter.loaded());
 
@@ -342,6 +350,10 @@ class KioskAppManagerTest : public InProcessBrowserTest {
   KioskAppManager* manager() const { return KioskAppManager::Get(); }
   FakeCWS* fake_cws() { return fake_cws_.get(); }
 
+ protected:
+  ScopedCrosSettingsTestHelper settings_helper_;
+  scoped_ptr<FakeOwnerSettingsService> owner_settings_service_;
+
  private:
   base::ScopedTempDir temp_dir_;
   scoped_ptr<FakeCWS> fake_cws_;
@@ -353,12 +365,12 @@ IN_PROC_BROWSER_TEST_F(KioskAppManagerTest, Basic) {
   // Add a couple of apps. Use "fake_app_x" that do not have data on the test
   // server to avoid pending data loads that could be lingering on tear down and
   // cause DCHECK failure in utility_process_host_impl.cc.
-  manager()->AddApp("fake_app_1");
-  manager()->AddApp("fake_app_2");
+  manager()->AddApp("fake_app_1", owner_settings_service_.get());
+  manager()->AddApp("fake_app_2", owner_settings_service_.get());
   EXPECT_EQ("fake_app_1,fake_app_2", GetAppIds());
 
   // Set an auto launch app.
-  manager()->SetAutoLaunchApp("fake_app_1");
+  manager()->SetAutoLaunchApp("fake_app_1", owner_settings_service_.get());
   EXPECT_EQ("fake_app_1", manager()->GetAutoLaunchApp());
 
   // Make sure that if an app was auto launched with zero delay, it is reflected
@@ -372,7 +384,7 @@ IN_PROC_BROWSER_TEST_F(KioskAppManagerTest, Basic) {
   EXPECT_TRUE(app.was_auto_launched_with_zero_delay);
 
   // Clear the auto launch app.
-  manager()->SetAutoLaunchApp("");
+  manager()->SetAutoLaunchApp("", owner_settings_service_.get());
   EXPECT_EQ("", manager()->GetAutoLaunchApp());
   EXPECT_FALSE(manager()->IsAutoLaunchEnabled());
 
@@ -382,7 +394,7 @@ IN_PROC_BROWSER_TEST_F(KioskAppManagerTest, Basic) {
   EXPECT_TRUE(app.was_auto_launched_with_zero_delay);
 
   // Set another auto launch app.
-  manager()->SetAutoLaunchApp("fake_app_2");
+  manager()->SetAutoLaunchApp("fake_app_2", owner_settings_service_.get());
   EXPECT_EQ("fake_app_2", manager()->GetAutoLaunchApp());
 
   // Check auto launch permissions.
@@ -391,24 +403,24 @@ IN_PROC_BROWSER_TEST_F(KioskAppManagerTest, Basic) {
   EXPECT_TRUE(manager()->IsAutoLaunchEnabled());
 
   // Remove the auto launch app.
-  manager()->RemoveApp("fake_app_2");
+  manager()->RemoveApp("fake_app_2", owner_settings_service_.get());
   EXPECT_EQ("fake_app_1", GetAppIds());
   EXPECT_EQ("", manager()->GetAutoLaunchApp());
 
   // Add the just removed auto launch app again and it should no longer be
   // the auto launch app.
-  manager()->AddApp("fake_app_2");
+  manager()->AddApp("fake_app_2", owner_settings_service_.get());
   EXPECT_EQ("", manager()->GetAutoLaunchApp());
-  manager()->RemoveApp("fake_app_2");
+  manager()->RemoveApp("fake_app_2", owner_settings_service_.get());
   EXPECT_EQ("fake_app_1", GetAppIds());
 
   // Set a none exist app as auto launch.
-  manager()->SetAutoLaunchApp("none_exist_app");
+  manager()->SetAutoLaunchApp("none_exist_app", owner_settings_service_.get());
   EXPECT_EQ("", manager()->GetAutoLaunchApp());
   EXPECT_FALSE(manager()->IsAutoLaunchEnabled());
 
   // Add an existing app again.
-  manager()->AddApp("fake_app_1");
+  manager()->AddApp("fake_app_1", owner_settings_service_.get());
   EXPECT_EQ("fake_app_1", GetAppIds());
 }
 
@@ -473,7 +485,7 @@ IN_PROC_BROWSER_TEST_F(KioskAppManagerTest, UpdateAppDataFromProfile) {
 
 IN_PROC_BROWSER_TEST_F(KioskAppManagerTest, BadApp) {
   AppDataLoadWaiter waiter(manager(), 2);
-  manager()->AddApp("unknown_app");
+  manager()->AddApp("unknown_app", owner_settings_service_.get());
   waiter.Wait();
   EXPECT_FALSE(waiter.loaded());
   EXPECT_EQ("", GetAppIds());
@@ -484,7 +496,7 @@ IN_PROC_BROWSER_TEST_F(KioskAppManagerTest, GoodApp) {
   //   chrome/test/data/chromeos/app_mode/webstore/inlineinstall/detail/app_1
   fake_cws()->SetNoUpdate("app_1");
   AppDataLoadWaiter waiter(manager(), 2);
-  manager()->AddApp("app_1");
+  manager()->AddApp("app_1", owner_settings_service_.get());
   waiter.Wait();
   EXPECT_TRUE(waiter.loaded());
 
@@ -533,7 +545,7 @@ IN_PROC_BROWSER_TEST_F(KioskAppManagerTest, RemoveApp) {
   EXPECT_EQ("1.0.0", version);
 
   // Remove the app now.
-  manager()->RemoveApp(kTestLocalFsKioskApp);
+  manager()->RemoveApp(kTestLocalFsKioskApp, owner_settings_service_.get());
   content::RunAllBlockingPoolTasksUntilIdle();
   manager()->GetApps(&apps);
   ASSERT_EQ(0u, apps.size());
@@ -615,7 +627,7 @@ IN_PROC_BROWSER_TEST_F(KioskAppManagerTest, UpdateAndRemoveApp) {
   EXPECT_TRUE(base::PathExists(v2_crx_path));
 
   // Remove the app now.
-  manager()->RemoveApp(kTestLocalFsKioskApp);
+  manager()->RemoveApp(kTestLocalFsKioskApp, owner_settings_service_.get());
   content::RunAllBlockingPoolTasksUntilIdle();
   manager()->GetApps(&apps);
   ASSERT_EQ(0u, apps.size());
diff --git a/chrome/browser/chromeos/attestation/attestation_policy_observer_unittest.cc b/chrome/browser/chromeos/attestation/attestation_policy_observer_unittest.cc
index 61fa81f..ebb0fd0 100644
--- a/chrome/browser/chromeos/attestation/attestation_policy_observer_unittest.cc
+++ b/chrome/browser/chromeos/attestation/attestation_policy_observer_unittest.cc
@@ -10,9 +10,7 @@
 #include "chrome/browser/chromeos/attestation/attestation_key_payload.pb.h"
 #include "chrome/browser/chromeos/attestation/attestation_policy_observer.h"
 #include "chrome/browser/chromeos/attestation/fake_certificate.h"
-#include "chrome/browser/chromeos/settings/cros_settings.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chromeos/attestation/mock_attestation_flow.h"
 #include "chromeos/dbus/mock_cryptohome_client.h"
 #include "chromeos/settings/cros_settings_names.h"
@@ -80,23 +78,11 @@ class AttestationPolicyObserverTest : public ::testing::Test {
  public:
   AttestationPolicyObserverTest()
       : ui_thread_(content::BrowserThread::UI, &message_loop_) {
-    // Remove the real DeviceSettingsProvider and replace it with a stub.
-    CrosSettings* cros_settings = CrosSettings::Get();
-    device_settings_provider_ =
-        cros_settings->GetProvider(kDeviceAttestationEnabled);
-    cros_settings->RemoveSettingsProvider(device_settings_provider_);
-    cros_settings->AddSettingsProvider(&stub_settings_provider_);
-    cros_settings->SetBoolean(kDeviceAttestationEnabled, true);
+    settings_helper_.ReplaceProvider(kDeviceAttestationEnabled);
+    settings_helper_.SetBoolean(kDeviceAttestationEnabled, true);
     policy_client_.SetDMToken("fake_dm_token");
   }
 
-  virtual ~AttestationPolicyObserverTest() {
-    // Restore the real DeviceSettingsProvider.
-    CrosSettings* cros_settings = CrosSettings::Get();
-    cros_settings->RemoveSettingsProvider(&stub_settings_provider_);
-    cros_settings->AddSettingsProvider(device_settings_provider_);
-  }
-
  protected:
   enum MockOptions {
     MOCK_KEY_EXISTS = 1,          // Configure so a certified key exists.
@@ -168,18 +154,14 @@ class AttestationPolicyObserverTest : public ::testing::Test {
 
   base::MessageLoopForUI message_loop_;
   content::TestBrowserThread ui_thread_;
-  ScopedTestDeviceSettingsService test_device_settings_service_;
-  ScopedTestCrosSettings test_cros_settings_;
-  CrosSettingsProvider* device_settings_provider_;
-  StubCrosSettingsProvider stub_settings_provider_;
+  ScopedCrosSettingsTestHelper settings_helper_;
   StrictMock<MockCryptohomeClient> cryptohome_client_;
   StrictMock<MockAttestationFlow> attestation_flow_;
   StrictMock<policy::MockCloudPolicyClient> policy_client_;
 };
 
 TEST_F(AttestationPolicyObserverTest, FeatureDisabled) {
-  CrosSettings* cros_settings = CrosSettings::Get();
-  cros_settings->SetBoolean(kDeviceAttestationEnabled, false);
+  settings_helper_.SetBoolean(kDeviceAttestationEnabled, false);
   Run();
 }
 
diff --git a/chrome/browser/chromeos/attestation/platform_verification_flow_unittest.cc b/chrome/browser/chromeos/attestation/platform_verification_flow_unittest.cc
index a3101e5..5319ddf 100644
--- a/chrome/browser/chromeos/attestation/platform_verification_flow_unittest.cc
+++ b/chrome/browser/chromeos/attestation/platform_verification_flow_unittest.cc
@@ -11,9 +11,7 @@
 #include "chrome/browser/chromeos/attestation/fake_certificate.h"
 #include "chrome/browser/chromeos/attestation/platform_verification_flow.h"
 #include "chrome/browser/chromeos/login/users/mock_user_manager.h"
-#include "chrome/browser/chromeos/settings/cros_settings.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chrome/browser/profiles/profile_impl.h"
 #include "chrome/common/pref_names.h"
 #include "chromeos/attestation/mock_attestation_flow.h"
@@ -153,20 +151,8 @@ class PlatformVerificationFlowTest : public ::testing::Test {
     callback_ = base::Bind(&PlatformVerificationFlowTest::FakeChallengeCallback,
                            base::Unretained(this));
 
-    // Configure the global cros_settings.
-    CrosSettings* cros_settings = CrosSettings::Get();
-    device_settings_provider_ =
-        cros_settings->GetProvider(kAttestationForContentProtectionEnabled);
-    cros_settings->RemoveSettingsProvider(device_settings_provider_);
-    cros_settings->AddSettingsProvider(&stub_settings_provider_);
-    cros_settings->SetBoolean(kAttestationForContentProtectionEnabled, true);
-  }
-
-  void TearDown() {
-    // Restore the real DeviceSettingsProvider.
-    CrosSettings* cros_settings = CrosSettings::Get();
-    cros_settings->RemoveSettingsProvider(&stub_settings_provider_);
-    cros_settings->AddSettingsProvider(device_settings_provider_);
+    settings_helper_.ReplaceProvider(kAttestationForContentProtectionEnabled);
+    settings_helper_.SetBoolean(kAttestationForContentProtectionEnabled, true);
   }
 
   void ExpectAttestationFlow() {
@@ -239,10 +225,7 @@ class PlatformVerificationFlowTest : public ::testing::Test {
   cryptohome::MockAsyncMethodCaller mock_async_caller_;
   CustomFakeCryptohomeClient fake_cryptohome_client_;
   FakeDelegate fake_delegate_;
-  CrosSettingsProvider* device_settings_provider_;
-  StubCrosSettingsProvider stub_settings_provider_;
-  ScopedTestDeviceSettingsService test_device_settings_service_;
-  ScopedTestCrosSettings test_cros_settings_;
+  ScopedCrosSettingsTestHelper settings_helper_;
   scoped_refptr<PlatformVerificationFlow> verifier_;
 
   // Controls result of FakeGetCertificate.
@@ -279,8 +262,7 @@ TEST_F(PlatformVerificationFlowTest, NotPermittedByUser) {
 }
 
 TEST_F(PlatformVerificationFlowTest, FeatureDisabledByPolicy) {
-  CrosSettings::Get()->SetBoolean(kAttestationForContentProtectionEnabled,
-                                  false);
+  settings_helper_.SetBoolean(kAttestationForContentProtectionEnabled, false);
   verifier_->ChallengePlatformKey(NULL, kTestID, kTestChallenge, callback_);
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(PlatformVerificationFlow::POLICY_REJECTED, result_);
diff --git a/chrome/browser/chromeos/login/auth/cryptohome_authenticator_unittest.cc b/chrome/browser/chromeos/login/auth/cryptohome_authenticator_unittest.cc
index c3dcd6e..2607ace 100644
--- a/chrome/browser/chromeos/login/auth/cryptohome_authenticator_unittest.cc
+++ b/chrome/browser/chromeos/login/auth/cryptohome_authenticator_unittest.cc
@@ -22,7 +22,7 @@
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/settings/device_settings_test_helper.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chrome/test/base/testing_browser_process.h"
 #include "chrome/test/base/testing_profile.h"
 #include "chrome/test/base/testing_profile_manager.h"
@@ -434,15 +434,9 @@ TEST_F(CryptohomeAuthenticatorTest, ResolveOwnerNeededFailedMount) {
   // and succeeded but we are in safe mode and the current user is not owner.
   state_->PresetCryptohomeStatus(true, cryptohome::MOUNT_ERROR_NONE);
   SetOwnerState(false, false);
-  // Remove the real DeviceSettingsProvider and replace it with a stub.
-  CrosSettingsProvider* device_settings_provider =
-      CrosSettings::Get()->GetProvider(chromeos::kReportDeviceVersionInfo);
-  EXPECT_TRUE(device_settings_provider != NULL);
-  EXPECT_TRUE(
-      CrosSettings::Get()->RemoveSettingsProvider(device_settings_provider));
-  StubCrosSettingsProvider stub_settings_provider;
-  CrosSettings::Get()->AddSettingsProvider(&stub_settings_provider);
-  CrosSettings::Get()->SetBoolean(kPolicyMissingMitigationMode, true);
+  ScopedCrosSettingsTestHelper settings_helper(false);
+  settings_helper.ReplaceProvider(kPolicyMissingMitigationMode);
+  settings_helper.SetBoolean(kPolicyMissingMitigationMode, true);
 
   // Initialize login state for this test to verify the login state is changed
   // to SAFE_MODE.
@@ -468,9 +462,6 @@ TEST_F(CryptohomeAuthenticatorTest, ResolveOwnerNeededFailedMount) {
   // Unset global objects used by this test.
   fake_cryptohome_client_->set_unmount_result(true);
   LoginState::Shutdown();
-  EXPECT_TRUE(
-      CrosSettings::Get()->RemoveSettingsProvider(&stub_settings_provider));
-  CrosSettings::Get()->AddSettingsProvider(device_settings_provider);
 }
 
 // Test the case that login switches to SafeMode and the Owner logs in, which
@@ -493,15 +484,9 @@ TEST_F(CryptohomeAuthenticatorTest, ResolveOwnerNeededSuccess) {
   // and succeeded but we are in safe mode and the current user is not owner.
   state_->PresetCryptohomeStatus(true, cryptohome::MOUNT_ERROR_NONE);
   SetOwnerState(false, false);
-  // Remove the real DeviceSettingsProvider and replace it with a stub.
-  CrosSettingsProvider* device_settings_provider =
-      CrosSettings::Get()->GetProvider(chromeos::kReportDeviceVersionInfo);
-  EXPECT_TRUE(device_settings_provider != NULL);
-  EXPECT_TRUE(
-      CrosSettings::Get()->RemoveSettingsProvider(device_settings_provider));
-  StubCrosSettingsProvider stub_settings_provider;
-  CrosSettings::Get()->AddSettingsProvider(&stub_settings_provider);
-  CrosSettings::Get()->SetBoolean(kPolicyMissingMitigationMode, true);
+  ScopedCrosSettingsTestHelper settings_helper(false);
+  settings_helper.ReplaceProvider(kPolicyMissingMitigationMode);
+  settings_helper.SetBoolean(kPolicyMissingMitigationMode, true);
 
   // Initialize login state for this test to verify the login state is changed
   // to SAFE_MODE.
@@ -526,9 +511,6 @@ TEST_F(CryptohomeAuthenticatorTest, ResolveOwnerNeededSuccess) {
   // Unset global objects used by this test.
   fake_cryptohome_client_->set_unmount_result(true);
   LoginState::Shutdown();
-  EXPECT_TRUE(
-      CrosSettings::Get()->RemoveSettingsProvider(&stub_settings_provider));
-  CrosSettings::Get()->AddSettingsProvider(device_settings_provider);
 }
 
 TEST_F(CryptohomeAuthenticatorTest, DriveFailedMount) {
diff --git a/chrome/browser/chromeos/login/kiosk_browsertest.cc b/chrome/browser/chromeos/login/kiosk_browsertest.cc
index b583daf..ad6d36b 100644
--- a/chrome/browser/chromeos/login/kiosk_browsertest.cc
+++ b/chrome/browser/chromeos/login/kiosk_browsertest.cc
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <vector>
+
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/desktop_background/desktop_background_controller_observer.h"
 #include "ash/shell.h"
@@ -14,11 +16,9 @@
 #include "base/path_service.h"
 #include "base/prefs/pref_service.h"
 #include "base/run_loop.h"
-#include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/synchronization/lock.h"
-#include "base/thread_task_runner_handle.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/app_mode/fake_cws.h"
 #include "chrome/browser/chromeos/app_mode/kiosk_app_launch_error.h"
@@ -35,13 +35,13 @@
 #include "chrome/browser/chromeos/login/users/mock_user_manager.h"
 #include "chrome/browser/chromeos/login/users/scoped_user_manager_enabler.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
+#include "chrome/browser/chromeos/ownership/fake_owner_settings_service.h"
+#include "chrome/browser/chromeos/policy/device_local_account.h"
 #include "chrome/browser/chromeos/policy/device_policy_cros_browser_test.h"
-#include "chrome/browser/chromeos/policy/proto/chrome_device_policy.pb.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
-#include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/settings/device_oauth2_token_service.h"
 #include "chrome/browser/chromeos/settings/device_oauth2_token_service_factory.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile_impl.h"
 #include "chrome/browser/profiles/profile_manager.h"
@@ -410,68 +410,6 @@ class AppDataLoadWaiter : public KioskAppManagerObserver {
   DISALLOW_COPY_AND_ASSIGN(AppDataLoadWaiter);
 };
 
-class CrosSettingsPermanentlyUntrustedMaker :
-    public DeviceSettingsService::Observer {
- public:
-  CrosSettingsPermanentlyUntrustedMaker();
-
-  // DeviceSettingsService::Observer:
-  void OwnershipStatusChanged() override;
-  void DeviceSettingsUpdated() override;
-  void OnDeviceSettingsServiceShutdown() override;
-
- private:
-  bool untrusted_check_running_;
-  base::RunLoop run_loop_;
-
-  void CheckIfUntrusted();
-
-  DISALLOW_COPY_AND_ASSIGN(CrosSettingsPermanentlyUntrustedMaker);
-};
-
-CrosSettingsPermanentlyUntrustedMaker::CrosSettingsPermanentlyUntrustedMaker()
-    : untrusted_check_running_(false) {
-  DeviceSettingsService::Get()->AddObserver(this);
-
-  policy::DevicePolicyCrosTestHelper().InstallOwnerKey();
-  DeviceSettingsService::Get()->OwnerKeySet(true);
-
-  run_loop_.Run();
-}
-
-void CrosSettingsPermanentlyUntrustedMaker::OwnershipStatusChanged() {
-  if (untrusted_check_running_)
-    return;
-
-  base::ThreadTaskRunnerHandle::Get()->PostTask(
-      FROM_HERE,
-      base::Bind(&CrosSettingsPermanentlyUntrustedMaker::CheckIfUntrusted,
-                 base::Unretained(this)));
-}
-
-void CrosSettingsPermanentlyUntrustedMaker::DeviceSettingsUpdated() {
-}
-
-void CrosSettingsPermanentlyUntrustedMaker::OnDeviceSettingsServiceShutdown() {
-}
-
-void CrosSettingsPermanentlyUntrustedMaker::CheckIfUntrusted() {
-  untrusted_check_running_ = true;
-  const CrosSettingsProvider::TrustedStatus trusted_status =
-      CrosSettings::Get()->PrepareTrustedValues(
-          base::Bind(&CrosSettingsPermanentlyUntrustedMaker::CheckIfUntrusted,
-                     base::Unretained(this)));
-  if (trusted_status == CrosSettingsProvider::TEMPORARILY_UNTRUSTED)
-    return;
-  untrusted_check_running_ = false;
-
-  if (trusted_status == CrosSettingsProvider::TRUSTED)
-    return;
-
-  DeviceSettingsService::Get()->RemoveObserver(this);
-  run_loop_.Quit();
-}
-
 }  // namespace
 
 // Boolean parameter is used to run this test for webview (true) and for
@@ -479,8 +417,10 @@ void CrosSettingsPermanentlyUntrustedMaker::CheckIfUntrusted() {
 class KioskTest : public OobeBaseTest,
                   public testing::WithParamInterface<bool> {
  public:
-  KioskTest() : use_consumer_kiosk_mode_(true),
-                fake_cws_(new FakeCWS) {
+  KioskTest()
+      : settings_helper_(false),
+        use_consumer_kiosk_mode_(true),
+        fake_cws_(new FakeCWS) {
     set_use_webview(GetParam());
     set_exit_when_last_browser_closes(false);
   }
@@ -511,9 +451,13 @@ class KioskTest : public OobeBaseTest,
     // Needed to avoid showing Gaia screen instead of owner signin for
     // consumer network down test cases.
     StartupUtils::MarkDeviceRegistered(base::Closure());
+    settings_helper_.ReplaceProvider(kAccountsPrefDeviceLocalAccounts);
+    owner_settings_service_ = settings_helper_.CreateOwnerSettingsService(
+        ProfileManager::GetPrimaryUserProfile());
   }
 
   void TearDownOnMainThread() override {
+    settings_helper_.RestoreProvider();
     AppLaunchController::SetNetworkTimeoutCallbackForTesting(NULL);
     AppLaunchSigninScreen::SetUserManagerForTesting(NULL);
 
@@ -541,8 +485,9 @@ class KioskTest : public OobeBaseTest,
     SetupTestAppUpdateCheck();
 
     // Remove then add to ensure NOTIFICATION_KIOSK_APPS_LOADED fires.
-    KioskAppManager::Get()->RemoveApp(test_app_id_);
-    KioskAppManager::Get()->AddApp(test_app_id_);
+    KioskAppManager::Get()->RemoveApp(test_app_id_,
+                                      owner_settings_service_.get());
+    KioskAppManager::Get()->AddApp(test_app_id_, owner_settings_service_.get());
   }
 
   void FireKioskAppSettingsChanged() {
@@ -559,8 +504,9 @@ class KioskTest : public OobeBaseTest,
   void ReloadAutolaunchKioskApps() {
     SetupTestAppUpdateCheck();
 
-    KioskAppManager::Get()->AddApp(test_app_id_);
-    KioskAppManager::Get()->SetAutoLaunchApp(test_app_id_);
+    KioskAppManager::Get()->AddApp(test_app_id_, owner_settings_service_.get());
+    KioskAppManager::Get()->SetAutoLaunchApp(test_app_id_,
+                                             owner_settings_service_.get());
   }
 
   void StartUIForAppLaunch() {
@@ -804,6 +750,9 @@ class KioskTest : public OobeBaseTest,
     use_consumer_kiosk_mode_ = use;
   }
 
+  ScopedCrosSettingsTestHelper settings_helper_;
+  scoped_ptr<FakeOwnerSettingsService> owner_settings_service_;
+
  private:
   bool use_consumer_kiosk_mode_;
   std::string test_app_id_;
@@ -994,7 +943,7 @@ IN_PROC_BROWSER_TEST_P(KioskTest, LaunchAppUserCancel) {
   OobeScreenWaiter splash_waiter(OobeDisplay::SCREEN_APP_LAUNCH_SPLASH);
   splash_waiter.Wait();
 
-  CrosSettings::Get()->SetBoolean(
+  settings_helper_.SetBoolean(
       kAccountsPrefDeviceLocalAccountAutoLoginBailoutEnabled, true);
   content::WindowedNotificationObserver signal(
       chrome::NOTIFICATION_APP_TERMINATING,
@@ -1218,7 +1167,8 @@ IN_PROC_BROWSER_TEST_P(KioskTest, DoNotLaunchWhenUntrusted) {
   SimulateNetworkOnline();
 
   // Make cros settings untrusted.
-  CrosSettingsPermanentlyUntrustedMaker();
+  settings_helper_.SetTrustedStatus(
+      CrosSettingsProvider::PERMANENTLY_UNTRUSTED);
 
   // Check that the attempt to start a kiosk app fails with an error.
   LaunchApp(test_app_id(), false);
@@ -1257,7 +1207,8 @@ IN_PROC_BROWSER_TEST_P(KioskTest, NoConsumerAutoLaunchWhenUntrusted) {
       base::FundamentalValue(true));
 
   // Make cros settings untrusted.
-  CrosSettingsPermanentlyUntrustedMaker();
+  settings_helper_.SetTrustedStatus(
+      CrosSettingsProvider::PERMANENTLY_UNTRUSTED);
 
   // Check that the attempt to auto-launch a kiosk app fails with an error.
   OobeScreenWaiter(OobeDisplay::SCREEN_ERROR_MESSAGE).Wait();
@@ -1281,7 +1232,8 @@ IN_PROC_BROWSER_TEST_P(KioskTest, NoEnterpriseAutoLaunchWhenUntrusted) {
   SimulateNetworkOnline();
 
   // Make cros settings untrusted.
-  CrosSettingsPermanentlyUntrustedMaker();
+  settings_helper_.SetTrustedStatus(
+      CrosSettingsProvider::PERMANENTLY_UNTRUSTED);
 
   // Trigger the code that handles auto-launch on enterprise devices. This would
   // normally be called from ShowLoginWizard(), which runs so early that it is
@@ -1313,7 +1265,19 @@ class KioskUpdateTest : public KioskTest {
     KioskTest::TearDown();
   }
 
-  void SetUpOnMainThread() override { KioskTest::SetUpOnMainThread(); }
+  void SetUpOnMainThread() override {
+    // For update tests, we cache the app in the PRE part, and then we load it
+    // in the test, so we need to both store the apps list on teardown (so that
+    // the app manager would accept existing files in its extension cache on the
+    // next startup) and copy the list to our stub settings provider as well.
+    settings_helper_.CopyStoredValue(kAccountsPrefDeviceLocalAccounts);
+    KioskTest::SetUpOnMainThread();
+  }
+
+  void TearDownOnMainThread() override {
+    settings_helper_.StoreCachedDeviceSetting(kAccountsPrefDeviceLocalAccounts);
+    KioskTest::TearDownOnMainThread();
+  }
 
   void PreCacheApp(const std::string& app_id,
                    const std::string& version,
@@ -1755,8 +1719,9 @@ class KioskEnterpriseTest : public KioskTest {
   }
 
   void SetUpInProcessBrowserTestFixture() override {
-    device_policy_test_helper_.MarkAsEnterpriseOwned();
-    device_policy_test_helper_.InstallOwnerKey();
+    policy::DevicePolicyCrosTestHelper::MarkAsEnterpriseOwnedBy(
+        kTestOwnerEmail);
+    settings_helper_.SetCurrentUserIsOwner(false);
 
     KioskTest::SetUpInProcessBrowserTestFixture();
   }
@@ -1799,41 +1764,21 @@ class KioskEnterpriseTest : public KioskTest {
     base::RunLoop().RunUntilIdle();
   }
 
-  static void StorePolicyCallback(const base::Closure& callback, bool result) {
-    ASSERT_TRUE(result);
-    callback.Run();
-  }
-
   void ConfigureKioskAppInPolicy(const std::string& account_id,
                                  const std::string& app_id,
                                  const std::string& update_url) {
-    em::DeviceLocalAccountsProto* accounts =
-        device_policy_test_helper_.device_policy()->payload()
-            .mutable_device_local_accounts();
-    em::DeviceLocalAccountInfoProto* account = accounts->add_account();
-    account->set_account_id(account_id);
-    account->set_type(
-        em::DeviceLocalAccountInfoProto::ACCOUNT_TYPE_KIOSK_APP);
-    account->mutable_kiosk_app()->set_app_id(app_id);
-    if (!update_url.empty())
-      account->mutable_kiosk_app()->set_update_url(update_url);
-    accounts->set_auto_login_id(account_id);
-    em::PolicyData& policy_data =
-        device_policy_test_helper_.device_policy()->policy_data();
-    policy_data.set_service_account_identity(kTestEnterpriseServiceAccountId);
-    device_policy_test_helper_.device_policy()->Build();
-
-    base::RunLoop run_loop;
-    DBusThreadManager::Get()->GetSessionManagerClient()->StoreDevicePolicy(
-        device_policy_test_helper_.device_policy()->GetBlob(),
-        base::Bind(&KioskEnterpriseTest::StorePolicyCallback,
-                   run_loop.QuitClosure()));
-    run_loop.Run();
-
-    DeviceSettingsService::Get()->Load();
-  }
-
-  policy::DevicePolicyCrosTestHelper device_policy_test_helper_;
+    settings_helper_.SetCurrentUserIsOwner(true);
+    std::vector<policy::DeviceLocalAccount> accounts;
+    accounts.push_back(
+        policy::DeviceLocalAccount(policy::DeviceLocalAccount::TYPE_KIOSK_APP,
+                                   account_id, app_id, update_url));
+    policy::SetDeviceLocalAccounts(owner_settings_service_.get(), accounts);
+    settings_helper_.SetString(kAccountsPrefDeviceLocalAccountAutoLoginId,
+                               account_id);
+    settings_helper_.SetString(kServiceAccountIdentity,
+                               kTestEnterpriseServiceAccountId);
+    settings_helper_.SetCurrentUserIsOwner(false);
+  }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(KioskEnterpriseTest);
diff --git a/chrome/browser/chromeos/login/users/user_manager_unittest.cc b/chrome/browser/chromeos/login/users/user_manager_unittest.cc
index 3765efa..b2e6368 100644
--- a/chrome/browser/chromeos/login/users/user_manager_unittest.cc
+++ b/chrome/browser/chromeos/login/users/user_manager_unittest.cc
@@ -11,14 +11,11 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_service.h"
 #include "base/run_loop.h"
-#include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/login/users/chrome_user_manager_impl.h"
 #include "chrome/browser/chromeos/login/users/scoped_user_manager_enabler.h"
 #include "chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager.h"
-#include "chrome/browser/chromeos/settings/cros_settings.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/test/base/scoped_testing_local_state.h"
 #include "chrome/test/base/testing_browser_process.h"
@@ -26,7 +23,6 @@
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/settings/cros_settings_names.h"
-#include "chromeos/settings/cros_settings_provider.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager.h"
 #include "content/public/common/content_switches.h"
@@ -50,7 +46,6 @@ class UnittestProfileManager : public ::ProfileManagerWithoutInit {
   }
 };
 
-
 class UserManagerTest : public testing::Test {
  protected:
   void SetUp() override {
@@ -59,15 +54,7 @@ class UserManagerTest : public testing::Test {
     command_line.AppendSwitch(
         chromeos::switches::kIgnoreUserProfileMappingForTests);
 
-    cros_settings_ = CrosSettings::Get();
-
-    // Replace the real DeviceSettingsProvider with a stub.
-    device_settings_provider_ =
-        cros_settings_->GetProvider(chromeos::kReportDeviceVersionInfo);
-    EXPECT_TRUE(device_settings_provider_);
-    EXPECT_TRUE(
-        cros_settings_->RemoveSettingsProvider(device_settings_provider_));
-    cros_settings_->AddSettingsProvider(&stub_settings_provider_);
+    settings_helper_.ReplaceProvider(kDeviceOwner);
 
     // Populate the stub DeviceSettingsProvider with valid values.
     SetDeviceSettings(false, "", false);
@@ -90,11 +77,6 @@ class UserManagerTest : public testing::Test {
     // Unregister the in-memory local settings instance.
     local_state_.reset();
 
-    // Restore the real DeviceSettingsProvider.
-    EXPECT_TRUE(
-      cros_settings_->RemoveSettingsProvider(&stub_settings_provider_));
-    cros_settings_->AddSettingsProvider(device_settings_provider_);
-
     // Shut down the DeviceSettingsService.
     DeviceSettingsService::Get()->UnsetSessionManager();
     TestingBrowserProcess::GetGlobal()->SetProfileManager(NULL);
@@ -140,14 +122,11 @@ class UserManagerTest : public testing::Test {
   void SetDeviceSettings(bool ephemeral_users_enabled,
                          const std::string &owner,
                          bool supervised_users_enabled) {
-    base::FundamentalValue
-        ephemeral_users_enabled_value(ephemeral_users_enabled);
-    stub_settings_provider_.Set(kAccountsPrefEphemeralUsersEnabled,
-        ephemeral_users_enabled_value);
-    base::StringValue owner_value(owner);
-    stub_settings_provider_.Set(kDeviceOwner, owner_value);
-    stub_settings_provider_.Set(kAccountsPrefSupervisedUsersEnabled,
-        base::FundamentalValue(supervised_users_enabled));
+    settings_helper_.SetBoolean(kAccountsPrefEphemeralUsersEnabled,
+                                ephemeral_users_enabled);
+    settings_helper_.SetString(kDeviceOwner, owner);
+    settings_helper_.SetBoolean(kAccountsPrefSupervisedUsersEnabled,
+                                supervised_users_enabled);
   }
 
   void RetrieveTrustedDevicePolicies() {
@@ -157,14 +136,9 @@ class UserManagerTest : public testing::Test {
  protected:
   content::TestBrowserThreadBundle thread_bundle_;
 
-  CrosSettings* cros_settings_;
-  CrosSettingsProvider* device_settings_provider_;
-  StubCrosSettingsProvider stub_settings_provider_;
+  ScopedCrosSettingsTestHelper settings_helper_;
   scoped_ptr<ScopedTestingLocalState> local_state_;
 
-  ScopedTestDeviceSettingsService test_device_settings_service_;
-  ScopedTestCrosSettings test_cros_settings_;
-
   scoped_ptr<ScopedUserManagerEnabler> user_manager_enabler_;
   base::ScopedTempDir temp_dir_;
 };
diff --git a/chrome/browser/chromeos/ownership/fake_owner_settings_service.cc b/chrome/browser/chromeos/ownership/fake_owner_settings_service.cc
index b515447..8042251 100644
--- a/chrome/browser/chromeos/ownership/fake_owner_settings_service.cc
+++ b/chrome/browser/chromeos/ownership/fake_owner_settings_service.cc
@@ -4,13 +4,27 @@
 
 #include "chrome/browser/chromeos/ownership/fake_owner_settings_service.h"
 
+#include "base/logging.h"
+#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "components/ownership/mock_owner_key_util.h"
+
 namespace chromeos {
 
+FakeOwnerSettingsService::FakeOwnerSettingsService(Profile* profile)
+    : OwnerSettingsServiceChromeOS(nullptr,
+                                   profile,
+                                   new ownership::MockOwnerKeyUtil()),
+      set_management_settings_result_(true),
+      settings_provider_(nullptr) {
+}
+
 FakeOwnerSettingsService::FakeOwnerSettingsService(
     Profile* profile,
-    const scoped_refptr<ownership::OwnerKeyUtil>& owner_key_util)
+    const scoped_refptr<ownership::OwnerKeyUtil>& owner_key_util,
+    StubCrosSettingsProvider* provider)
     : OwnerSettingsServiceChromeOS(nullptr, profile, owner_key_util),
-      set_management_settings_result_(true) {
+      set_management_settings_result_(true),
+      settings_provider_(provider) {
 }
 
 FakeOwnerSettingsService::~FakeOwnerSettingsService() {
@@ -23,4 +37,11 @@ void FakeOwnerSettingsService::SetManagementSettings(
   callback.Run(set_management_settings_result_);
 }
 
+bool FakeOwnerSettingsService::Set(const std::string& setting,
+                                   const base::Value& value) {
+  CHECK(settings_provider_);
+  settings_provider_->Set(setting, value);
+  return true;
+}
+
 }  // namespace chromeos
diff --git a/chrome/browser/chromeos/ownership/fake_owner_settings_service.h b/chrome/browser/chromeos/ownership/fake_owner_settings_service.h
index bed4d06..3f785c1 100644
--- a/chrome/browser/chromeos/ownership/fake_owner_settings_service.h
+++ b/chrome/browser/chromeos/ownership/fake_owner_settings_service.h
@@ -17,11 +17,15 @@ class OwnerKeyUtil;
 
 namespace chromeos {
 
+class StubCrosSettingsProvider;
+
 class FakeOwnerSettingsService : public OwnerSettingsServiceChromeOS {
  public:
+  explicit FakeOwnerSettingsService(Profile* profile);
   FakeOwnerSettingsService(
       Profile* profile,
-      const scoped_refptr<ownership::OwnerKeyUtil>& owner_key_util);
+      const scoped_refptr<ownership::OwnerKeyUtil>& owner_key_util,
+      StubCrosSettingsProvider* provider);
   ~FakeOwnerSettingsService() override;
 
   void set_set_management_settings_result(bool success) {
@@ -36,10 +40,12 @@ class FakeOwnerSettingsService : public OwnerSettingsServiceChromeOS {
   void SetManagementSettings(
       const ManagementSettings& settings,
       const OnManagementSettingsSetCallback& callback) override;
+  bool Set(const std::string& setting, const base::Value& value) override;
 
  private:
   bool set_management_settings_result_;
   ManagementSettings last_settings_;
+  StubCrosSettingsProvider* settings_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeOwnerSettingsService);
 };
diff --git a/chrome/browser/chromeos/ownership/owner_settings_service_chromeos.cc b/chrome/browser/chromeos/ownership/owner_settings_service_chromeos.cc
index bac0fba..a96f0aa 100644
--- a/chrome/browser/chromeos/ownership/owner_settings_service_chromeos.cc
+++ b/chrome/browser/chromeos/ownership/owner_settings_service_chromeos.cc
@@ -174,6 +174,7 @@ bool CheckManagementModeTransition(policy::ManagementMode current_mode,
   NOTREACHED();
   return false;
 }
+
 }  // namespace
 
 OwnerSettingsServiceChromeOS::ManagementSettings::ManagementSettings() {
diff --git a/chrome/browser/chromeos/policy/consumer_unenrollment_handler_unittest.cc b/chrome/browser/chromeos/policy/consumer_unenrollment_handler_unittest.cc
index cacf396..1a9ba8b 100644
--- a/chrome/browser/chromeos/policy/consumer_unenrollment_handler_unittest.cc
+++ b/chrome/browser/chromeos/policy/consumer_unenrollment_handler_unittest.cc
@@ -59,9 +59,8 @@ class ConsumerUnenrollmentHandlerTest
         base::ThreadTaskRunnerHandle::Get()));
 
     // Set up FakeOwnerSettingsService.
-    fake_owner_settings_service_.reset(
-        new chromeos::FakeOwnerSettingsService(
-            profile_.get(), owner_key_util_));
+    fake_owner_settings_service_.reset(new chromeos::FakeOwnerSettingsService(
+        profile_.get(), owner_key_util_, nullptr));
     chromeos::OwnerSettingsServiceChromeOS::ManagementSettings settings;
     settings.management_mode = policy::MANAGEMENT_MODE_CONSUMER_MANAGED;
     settings.request_token = "fake_request_token";
diff --git a/chrome/browser/chromeos/policy/device_local_account.cc b/chrome/browser/chromeos/policy/device_local_account.cc
index 80b89b2..63c7a14 100644
--- a/chrome/browser/chromeos/policy/device_local_account.cc
+++ b/chrome/browser/chromeos/policy/device_local_account.cc
@@ -12,6 +12,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/values.h"
+#include "chrome/browser/chromeos/ownership/owner_settings_service_chromeos.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chromeos/login/user_names.h"
 #include "chromeos/settings/cros_settings_names.h"
@@ -91,9 +92,8 @@ bool IsDeviceLocalAccountUser(const std::string& user_id,
   return true;
 }
 
-void SetDeviceLocalAccounts(
-    chromeos::CrosSettings* cros_settings,
-    const std::vector<DeviceLocalAccount>& accounts) {
+void SetDeviceLocalAccounts(chromeos::OwnerSettingsServiceChromeOS* service,
+                            const std::vector<DeviceLocalAccount>& accounts) {
   base::ListValue list;
   for (std::vector<DeviceLocalAccount>::const_iterator it = accounts.begin();
        it != accounts.end(); ++it) {
@@ -117,7 +117,7 @@ void SetDeviceLocalAccounts(
     list.Append(entry.release());
   }
 
-  cros_settings->Set(chromeos::kAccountsPrefDeviceLocalAccounts, list);
+  service->Set(chromeos::kAccountsPrefDeviceLocalAccounts, list);
 }
 
 std::vector<DeviceLocalAccount> GetDeviceLocalAccounts(
diff --git a/chrome/browser/chromeos/policy/device_local_account.h b/chrome/browser/chromeos/policy/device_local_account.h
index 69a7480..8827119 100644
--- a/chrome/browser/chromeos/policy/device_local_account.h
+++ b/chrome/browser/chromeos/policy/device_local_account.h
@@ -10,6 +10,7 @@
 
 namespace chromeos {
 class CrosSettings;
+class OwnerSettingsServiceChromeOS;
 }
 
 namespace policy {
@@ -64,12 +65,11 @@ std::string GenerateDeviceLocalAccountUserId(const std::string& account_id,
 bool IsDeviceLocalAccountUser(const std::string& user_id,
                               DeviceLocalAccount::Type* type);
 
-// Stores a list of device-local accounts in |cros_settings|. The accounts are
-// stored as a list of dictionaries with each dictionary containing the
-// information about one |DeviceLocalAccount|.
-void SetDeviceLocalAccounts(
-    chromeos::CrosSettings* cros_settings,
-    const std::vector<DeviceLocalAccount>& accounts);
+// Stores a list of device-local accounts in |service|. The accounts are stored
+// as a list of dictionaries with each dictionary containing the information
+// about one |DeviceLocalAccount|.
+void SetDeviceLocalAccounts(chromeos::OwnerSettingsServiceChromeOS* service,
+                            const std::vector<DeviceLocalAccount>& accounts);
 
 // Retrieves a list of device-local accounts from |cros_settings|.
 std::vector<DeviceLocalAccount> GetDeviceLocalAccounts(
diff --git a/chrome/browser/chromeos/policy/device_policy_cros_browser_test.cc b/chrome/browser/chromeos/policy/device_policy_cros_browser_test.cc
index 59e8401..8e78071 100644
--- a/chrome/browser/chromeos/policy/device_policy_cros_browser_test.cc
+++ b/chrome/browser/chromeos/policy/device_policy_cros_browser_test.cc
@@ -4,7 +4,6 @@
 
 #include "chrome/browser/chromeos/policy/device_policy_cros_browser_test.h"
 
-#include <string>
 #include <vector>
 
 #include "base/files/file_path.h"
@@ -31,13 +30,14 @@ DevicePolicyCrosTestHelper::DevicePolicyCrosTestHelper() {}
 
 DevicePolicyCrosTestHelper::~DevicePolicyCrosTestHelper() {}
 
-void DevicePolicyCrosTestHelper::MarkAsEnterpriseOwned() {
+// static
+void DevicePolicyCrosTestHelper::MarkAsEnterpriseOwnedBy(
+    const std::string& user_name) {
   OverridePaths();
 
   const std::string install_attrs_blob(
       EnterpriseInstallAttributes::
-          GetEnterpriseOwnedInstallAttributesBlobForTesting(
-              device_policy_.policy_data().username()));
+          GetEnterpriseOwnedInstallAttributesBlobForTesting(user_name));
 
   base::FilePath install_attrs_file;
   ASSERT_TRUE(
@@ -48,6 +48,10 @@ void DevicePolicyCrosTestHelper::MarkAsEnterpriseOwned() {
                             install_attrs_blob.size()));
 }
 
+void DevicePolicyCrosTestHelper::MarkAsEnterpriseOwned() {
+  MarkAsEnterpriseOwnedBy(device_policy_.policy_data().username());
+}
+
 void DevicePolicyCrosTestHelper::InstallOwnerKey() {
   OverridePaths();
 
@@ -63,6 +67,7 @@ void DevicePolicyCrosTestHelper::InstallOwnerKey() {
       static_cast<int>(owner_key_bits.size()));
 }
 
+// static
 void DevicePolicyCrosTestHelper::OverridePaths() {
   // This is usually done by ChromeBrowserMainChromeOS, but some tests
   // use the overridden paths before ChromeBrowserMain starts. Make sure that
diff --git a/chrome/browser/chromeos/policy/device_policy_cros_browser_test.h b/chrome/browser/chromeos/policy/device_policy_cros_browser_test.h
index e6e90a9..ca52897 100644
--- a/chrome/browser/chromeos/policy/device_policy_cros_browser_test.h
+++ b/chrome/browser/chromeos/policy/device_policy_cros_browser_test.h
@@ -5,6 +5,8 @@
 #ifndef CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_POLICY_CROS_BROWSER_TEST_H_
 #define CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_POLICY_CROS_BROWSER_TEST_H_
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "chrome/browser/chromeos/policy/device_policy_builder.h"
@@ -25,6 +27,7 @@ class DevicePolicyCrosTestHelper {
   // Marks the device as enterprise-owned. Must be called to make device
   // policies apply Chrome-wide. If this is not called, device policies will
   // affect CrosSettings only.
+  static void MarkAsEnterpriseOwnedBy(const std::string& user_name);
   void MarkAsEnterpriseOwned();
 
   // Writes the owner key to disk. To be called before installing a policy.
@@ -33,7 +36,7 @@ class DevicePolicyCrosTestHelper {
   DevicePolicyBuilder* device_policy() { return &device_policy_; }
 
  private:
-  void OverridePaths();
+  static void OverridePaths();
 
   // Carries Chrome OS device policies for tests.
   DevicePolicyBuilder device_policy_;
diff --git a/chrome/browser/chromeos/policy/device_status_collector_browsertest.cc b/chrome/browser/chromeos/policy/device_status_collector_browsertest.cc
index c031b59..dbd79a7 100644
--- a/chrome/browser/chromeos/policy/device_status_collector_browsertest.cc
+++ b/chrome/browser/chromeos/policy/device_status_collector_browsertest.cc
@@ -18,12 +18,11 @@
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/chromeos/login/users/mock_user_manager.h"
 #include "chrome/browser/chromeos/login/users/scoped_user_manager_enabler.h"
+#include "chrome/browser/chromeos/ownership/fake_owner_settings_service.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/policy/device_local_account.h"
 #include "chrome/browser/chromeos/policy/stub_enterprise_install_attributes.h"
-#include "chrome/browser/chromeos/settings/cros_settings.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/testing_browser_process.h"
 #include "chromeos/dbus/cros_disks_client.h"
@@ -37,7 +36,6 @@
 #include "chromeos/network/network_state.h"
 #include "chromeos/network/network_state_handler.h"
 #include "chromeos/settings/cros_settings_names.h"
-#include "chromeos/settings/cros_settings_provider.h"
 #include "chromeos/system/fake_statistics_provider.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/geolocation_provider.h"
@@ -230,20 +228,20 @@ namespace policy {
 class DeviceStatusCollectorTest : public testing::Test {
  public:
   DeviceStatusCollectorTest()
-    : ui_thread_(content::BrowserThread::UI, &message_loop_),
-      file_thread_(content::BrowserThread::FILE, &message_loop_),
-      io_thread_(content::BrowserThread::IO, &message_loop_),
-      install_attributes_("managed.com",
-                          "user@managed.com",
-                          "device_id",
-                          DEVICE_MODE_ENTERPRISE),
-      user_manager_(new chromeos::MockUserManager()),
-      user_manager_enabler_(user_manager_),
-      fake_device_local_account_(
-          policy::DeviceLocalAccount::TYPE_KIOSK_APP,
-          kKioskAccountId,
-          kKioskAppId,
-          std::string() /* kiosk_app_update_url */) {
+      : ui_thread_(content::BrowserThread::UI, &message_loop_),
+        file_thread_(content::BrowserThread::FILE, &message_loop_),
+        io_thread_(content::BrowserThread::IO, &message_loop_),
+        install_attributes_("managed.com",
+                            "user@managed.com",
+                            "device_id",
+                            DEVICE_MODE_ENTERPRISE),
+        settings_helper_(false),
+        user_manager_(new chromeos::MockUserManager()),
+        user_manager_enabler_(user_manager_),
+        fake_device_local_account_(policy::DeviceLocalAccount::TYPE_KIOSK_APP,
+                                   kKioskAccountId,
+                                   kKioskAppId,
+                                   std::string() /* kiosk_app_update_url */) {
     // Run this test with a well-known timezone so that Time::LocalMidnight()
     // returns the same values on all machines.
     scoped_ptr<base::Environment> env(base::Environment::Create());
@@ -274,14 +272,9 @@ class DeviceStatusCollectorTest : public testing::Test {
     DiskMountManager::InitializeForTesting(mock_disk_mount_manager.release());
     TestingDeviceStatusCollector::RegisterPrefs(prefs_.registry());
 
-    // Remove the real DeviceSettingsProvider and replace it with a stub.
-    cros_settings_ = chromeos::CrosSettings::Get();
-    device_settings_provider_ =
-        cros_settings_->GetProvider(chromeos::kReportDeviceVersionInfo);
-    EXPECT_TRUE(device_settings_provider_ != NULL);
-    EXPECT_TRUE(
-        cros_settings_->RemoveSettingsProvider(device_settings_provider_));
-    cros_settings_->AddSettingsProvider(&stub_settings_provider_);
+    settings_helper_.ReplaceProvider(chromeos::kReportDeviceActivityTimes);
+    owner_settings_service_ =
+        settings_helper_.CreateOwnerSettingsService(nullptr);
 
     RestartStatusCollector(base::Bind(&GetEmptyVolumeInfo),
                            base::Bind(&GetEmptyCPUStatistics));
@@ -301,18 +294,16 @@ class DeviceStatusCollectorTest : public testing::Test {
     message_loop_.RunUntilIdle();
     storage::ExternalMountPoints::GetSystemInstance()->RevokeAllFileSystems();
     DiskMountManager::Shutdown();
-
-    // Restore the real DeviceSettingsProvider.
-    EXPECT_TRUE(
-        cros_settings_->RemoveSettingsProvider(&stub_settings_provider_));
-    cros_settings_->AddSettingsProvider(device_settings_provider_);
   }
 
   void SetUp() override {
     // Disable network interface reporting since it requires additional setup.
-    cros_settings_->SetBoolean(chromeos::kReportDeviceNetworkInterfaces, false);
+    settings_helper_.SetBoolean(chromeos::kReportDeviceNetworkInterfaces,
+                                false);
   }
 
+  void TearDown() override { settings_helper_.RestoreProvider(); }
+
   void RestartStatusCollector(
       const policy::DeviceStatusCollector::VolumeInfoFetcher& volume_info,
       const policy::DeviceStatusCollector::CPUStatisticsFetcher& cpu_stats) {
@@ -370,7 +361,7 @@ class DeviceStatusCollectorTest : public testing::Test {
   void MockRunningKioskApp(const DeviceLocalAccount& account) {
     std::vector<DeviceLocalAccount> accounts;
     accounts.push_back(account);
-    SetDeviceLocalAccounts(cros_settings_, accounts);
+    SetDeviceLocalAccounts(owner_settings_service_.get(), accounts);
     user_manager_->CreateKioskAppUser(account.user_id);
     EXPECT_CALL(*user_manager_, IsLoggedInAsKioskApp()).WillRepeatedly(
         Return(true));
@@ -396,9 +387,8 @@ class DeviceStatusCollectorTest : public testing::Test {
   DiskMountManager::MountPointMap mount_point_map_;
   chromeos::ScopedTestDeviceSettingsService test_device_settings_service_;
   chromeos::ScopedTestCrosSettings test_cros_settings_;
-  chromeos::CrosSettings* cros_settings_;
-  chromeos::CrosSettingsProvider* device_settings_provider_;
-  chromeos::StubCrosSettingsProvider stub_settings_provider_;
+  chromeos::ScopedCrosSettingsTestHelper settings_helper_;
+  scoped_ptr<chromeos::FakeOwnerSettingsService> owner_settings_service_;
   chromeos::MockUserManager* user_manager_;
   chromeos::ScopedUserManagerEnabler user_manager_enabler_;
   em::DeviceStatusReportRequest status_;
@@ -412,7 +402,7 @@ TEST_F(DeviceStatusCollectorTest, AllIdle) {
     ui::IDLE_STATE_IDLE,
     ui::IDLE_STATE_IDLE
   };
-  cros_settings_->SetBoolean(chromeos::kReportDeviceActivityTimes, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceActivityTimes, true);
 
   // Test reporting with no data.
   GetStatus();
@@ -439,7 +429,7 @@ TEST_F(DeviceStatusCollectorTest, AllActive) {
     ui::IDLE_STATE_ACTIVE,
     ui::IDLE_STATE_ACTIVE
   };
-  cros_settings_->SetBoolean(chromeos::kReportDeviceActivityTimes, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceActivityTimes, true);
 
   // Test a single active sample.
   status_collector_->Simulate(test_states, 1);
@@ -466,7 +456,7 @@ TEST_F(DeviceStatusCollectorTest, MixedStates) {
     ui::IDLE_STATE_IDLE,
     ui::IDLE_STATE_ACTIVE
   };
-  cros_settings_->SetBoolean(chromeos::kReportDeviceActivityTimes, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceActivityTimes, true);
   status_collector_->Simulate(test_states,
                               sizeof(test_states) / sizeof(ui::IdleState));
   GetStatus();
@@ -482,7 +472,7 @@ TEST_F(DeviceStatusCollectorTest, StateKeptInPref) {
     ui::IDLE_STATE_IDLE,
     ui::IDLE_STATE_IDLE
   };
-  cros_settings_->SetBoolean(chromeos::kReportDeviceActivityTimes, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceActivityTimes, true);
   status_collector_->Simulate(test_states,
                               sizeof(test_states) / sizeof(ui::IdleState));
 
@@ -507,7 +497,7 @@ TEST_F(DeviceStatusCollectorTest, Times) {
     ui::IDLE_STATE_IDLE,
     ui::IDLE_STATE_IDLE
   };
-  cros_settings_->SetBoolean(chromeos::kReportDeviceActivityTimes, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceActivityTimes, true);
   status_collector_->Simulate(test_states,
                               sizeof(test_states) / sizeof(ui::IdleState));
   GetStatus();
@@ -521,7 +511,7 @@ TEST_F(DeviceStatusCollectorTest, MaxStoredPeriods) {
   };
   const int kMaxDays = 10;
 
-  cros_settings_->SetBoolean(chromeos::kReportDeviceActivityTimes, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceActivityTimes, true);
   status_collector_->set_max_stored_past_activity_days(kMaxDays - 1);
   status_collector_->set_max_stored_future_activity_days(1);
   Time baseline = Time::Now().LocalMidnight();
@@ -576,7 +566,7 @@ TEST_F(DeviceStatusCollectorTest, ActivityTimesEnabledByDefault) {
 
 TEST_F(DeviceStatusCollectorTest, ActivityTimesOff) {
   // Device activity times should not be reported if explicitly disabled.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceActivityTimes, false);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceActivityTimes, false);
 
   ui::IdleState test_states[] = {
     ui::IDLE_STATE_ACTIVE,
@@ -594,7 +584,7 @@ TEST_F(DeviceStatusCollectorTest, ActivityCrossingMidnight) {
   ui::IdleState test_states[] = {
     ui::IDLE_STATE_ACTIVE
   };
-  cros_settings_->SetBoolean(chromeos::kReportDeviceActivityTimes, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceActivityTimes, true);
 
   // Set the baseline time to 10 seconds after midnight.
   status_collector_->SetBaselineTime(
@@ -626,7 +616,7 @@ TEST_F(DeviceStatusCollectorTest, ActivityTimesKeptUntilSubmittedSuccessfully) {
     ui::IDLE_STATE_ACTIVE,
     ui::IDLE_STATE_ACTIVE,
   };
-  cros_settings_->SetBoolean(chromeos::kReportDeviceActivityTimes, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceActivityTimes, true);
 
   status_collector_->Simulate(test_states, 2);
   GetStatus();
@@ -654,14 +644,14 @@ TEST_F(DeviceStatusCollectorTest, DevSwitchBootMode) {
   EXPECT_EQ("Verified", status_.boot_mode());
 
   // Test that boot mode data is not reported if the pref turned off.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceBootMode, false);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceBootMode, false);
 
   GetStatus();
   EXPECT_FALSE(status_.has_boot_mode());
 
   // Turn the pref on, and check that the status is reported iff the
   // statistics provider returns valid data.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceBootMode, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceBootMode, true);
 
   fake_statistics_provider_.SetMachineStatistic(
       chromeos::system::kDevSwitchBootKey, "(error)");
@@ -695,13 +685,13 @@ TEST_F(DeviceStatusCollectorTest, VersionInfo) {
 
   // When the pref to collect this data is not enabled, expect that none of
   // the fields are present in the protobuf.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceVersionInfo, false);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceVersionInfo, false);
   GetStatus();
   EXPECT_FALSE(status_.has_browser_version());
   EXPECT_FALSE(status_.has_os_version());
   EXPECT_FALSE(status_.has_firmware_version());
 
-  cros_settings_->SetBoolean(chromeos::kReportDeviceVersionInfo, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceVersionInfo, true);
   GetStatus();
   EXPECT_TRUE(status_.has_browser_version());
   EXPECT_TRUE(status_.has_os_version());
@@ -733,7 +723,7 @@ TEST_F(DeviceStatusCollectorTest, Location) {
   // Check that when device location reporting is enabled and a valid fix is
   // available, the location is reported and is stored in local state.
   SetMockPositionToReturnNext(valid_fix);
-  cros_settings_->SetBoolean(chromeos::kReportDeviceLocation, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceLocation, true);
   EXPECT_FALSE(prefs_.GetDictionary(prefs::kDeviceLocation)->empty());
   CheckThatAValidLocationIsReported();
 
@@ -748,7 +738,7 @@ TEST_F(DeviceStatusCollectorTest, Location) {
   // Check that after disabling location reporting again, the last known
   // location has been cleared from local state and is no longer reported.
   SetMockPositionToReturnNext(valid_fix);
-  cros_settings_->SetBoolean(chromeos::kReportDeviceLocation, false);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceLocation, false);
   // Allow the new pref to propagate to the status collector.
   message_loop_.RunUntilIdle();
   EXPECT_TRUE(prefs_.GetDictionary(prefs::kDeviceLocation)->empty());
@@ -757,7 +747,7 @@ TEST_F(DeviceStatusCollectorTest, Location) {
   // Check that after enabling location reporting again, an error is reported
   // if no valid fix is available.
   SetMockPositionToReturnNext(invalid_fix);
-  cros_settings_->SetBoolean(chromeos::kReportDeviceLocation, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceLocation, true);
   // Allow the new pref to propagate to the status collector.
   message_loop_.RunUntilIdle();
   CheckThatALocationErrorIsReported();
@@ -777,7 +767,7 @@ TEST_F(DeviceStatusCollectorTest, ReportUsers) {
   EXPECT_EQ(6, status_.user_size());
 
   // Verify that users are reported after enabling the setting.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceUsers, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceUsers, true);
   GetStatus();
   EXPECT_EQ(6, status_.user_size());
   EXPECT_EQ(em::DeviceUser::USER_TYPE_MANAGED, status_.user(0).type());
@@ -794,7 +784,7 @@ TEST_F(DeviceStatusCollectorTest, ReportUsers) {
   EXPECT_EQ("user5@managed.com", status_.user(5).email());
 
   // Verify that users are no longer reported if setting is disabled.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceUsers, false);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceUsers, false);
   GetStatus();
   EXPECT_EQ(0, status_.user_size());
 }
@@ -843,7 +833,7 @@ TEST_F(DeviceStatusCollectorTest, TestVolumeInfo) {
   }
 
   // Now turn off hardware status reporting - should have no data.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceHardwareStatus, false);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceHardwareStatus, false);
   GetStatus();
   EXPECT_EQ(0, status_.volume_info_size());
 }
@@ -903,21 +893,21 @@ TEST_F(DeviceStatusCollectorTest, DISABLED_TestCPUSamples) {
     EXPECT_EQ(0, utilization);
 
   // Turning off hardware reporting should not report CPU utilization.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceHardwareStatus, false);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceHardwareStatus, false);
   GetStatus();
   EXPECT_EQ(0, status_.cpu_utilization_pct().size());
 }
 
 TEST_F(DeviceStatusCollectorTest, NoSessionStatusIfNotKioskMode) {
   // Should not report session status if we don't have an active kiosk app.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceSessionStatus, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceSessionStatus, true);
   em::SessionStatusReportRequest session_status;
   EXPECT_FALSE(status_collector_->GetDeviceSessionStatus(&session_status));
 }
 
 TEST_F(DeviceStatusCollectorTest, NoSessionStatusIfSessionReportingDisabled) {
   // Should not report session status if session status reporting is disabled.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceSessionStatus, false);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceSessionStatus, false);
   status_collector_->set_kiosk_account(make_scoped_ptr(
       new policy::DeviceLocalAccount(fake_device_local_account_)).Pass());
   // Set up a device-local account for single-app kiosk mode.
@@ -928,7 +918,7 @@ TEST_F(DeviceStatusCollectorTest, NoSessionStatusIfSessionReportingDisabled) {
 }
 
 TEST_F(DeviceStatusCollectorTest, ReportSessionStatus) {
-  cros_settings_->SetBoolean(chromeos::kReportDeviceSessionStatus, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceSessionStatus, true);
   status_collector_->set_kiosk_account(make_scoped_ptr(
       new policy::DeviceLocalAccount(fake_device_local_account_)).Pass());
 
@@ -1164,13 +1154,13 @@ TEST_F(DeviceStatusCollectorNetworkInterfacesTest, NetworkInterfaces) {
   EXPECT_LT(0, status_.network_state_size());
 
   // No interfaces should be reported if the policy is off.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceNetworkInterfaces, false);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceNetworkInterfaces, false);
   GetStatus();
   EXPECT_EQ(0, status_.network_interface_size());
   EXPECT_EQ(0, status_.network_state_size());
 
   // Switch the policy on and verify the interface list is present.
-  cros_settings_->SetBoolean(chromeos::kReportDeviceNetworkInterfaces, true);
+  settings_helper_.SetBoolean(chromeos::kReportDeviceNetworkInterfaces, true);
   GetStatus();
 
   int count = 0;
diff --git a/chrome/browser/chromeos/policy/extension_cache_unittest.cc b/chrome/browser/chromeos/policy/extension_cache_unittest.cc
index 0b88894..5191e0c 100644
--- a/chrome/browser/chromeos/policy/extension_cache_unittest.cc
+++ b/chrome/browser/chromeos/policy/extension_cache_unittest.cc
@@ -10,14 +10,11 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/run_loop.h"
 #include "base/time/time.h"
-#include "chrome/browser/chromeos/settings/cros_settings.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chrome/browser/extensions/updater/chromeos_extension_cache_delegate.h"
 #include "chrome/browser/extensions/updater/extension_cache_impl.h"
 #include "chrome/browser/extensions/updater/local_extension_cache.h"
 #include "chromeos/settings/cros_settings_names.h"
-#include "chromeos/settings/cros_settings_provider.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -58,39 +55,14 @@ static base::FilePath CreateExtensionFile(const base::FilePath& dir,
 }  // namespace
 
 class ExtensionCacheTest : public testing::Test {
- public:
-  void SetUp() override {
-    // Swap out the DeviceSettingsProvider with our stub settings provider
-    // so we can set values for maximum extension cache size.
-    chromeos::CrosSettings* const cros_settings = chromeos::CrosSettings::Get();
-    device_settings_provider_ =
-        cros_settings->GetProvider(chromeos::kExtensionCacheSize);
-    EXPECT_TRUE(device_settings_provider_);
-    EXPECT_TRUE(
-        cros_settings->RemoveSettingsProvider(device_settings_provider_));
-    cros_settings->AddSettingsProvider(&stub_settings_provider_);
-  }
-
-  void TearDown() override {
-    // Restore the real DeviceSettingsProvider.
-    chromeos::CrosSettings* const cros_settings = chromeos::CrosSettings::Get();
-    EXPECT_TRUE(
-        cros_settings->RemoveSettingsProvider(&stub_settings_provider_));
-    cros_settings->AddSettingsProvider(device_settings_provider_);
-  }
-
-  // Helpers used to mock out cros settings.
-  chromeos::ScopedTestDeviceSettingsService test_device_settings_service_;
-  chromeos::ScopedTestCrosSettings test_cros_settings_;
-  chromeos::CrosSettingsProvider* device_settings_provider_ = nullptr;
-  chromeos::StubCrosSettingsProvider stub_settings_provider_;
-
+ protected:
   content::TestBrowserThreadBundle thread_bundle_;
+  chromeos::ScopedCrosSettingsTestHelper settings_helper_;
 };
 
 TEST_F(ExtensionCacheTest, SizePolicy) {
-  chromeos::CrosSettings::Get()->SetInteger(chromeos::kExtensionCacheSize,
-                                            kMaxCacheSize);
+  settings_helper_.ReplaceProvider(chromeos::kExtensionCacheSize);
+  settings_helper_.SetInteger(chromeos::kExtensionCacheSize, kMaxCacheSize);
 
   // Create and initialize local cache.
   const base::Time now = base::Time::Now();
diff --git a/chrome/browser/chromeos/policy/heartbeat_scheduler_unittest.cc b/chrome/browser/chromeos/policy/heartbeat_scheduler_unittest.cc
index 7a1a05c..8e5686b 100644
--- a/chrome/browser/chromeos/policy/heartbeat_scheduler_unittest.cc
+++ b/chrome/browser/chromeos/policy/heartbeat_scheduler_unittest.cc
@@ -6,9 +6,7 @@
 
 #include "base/strings/string_number_conversions.h"
 #include "base/test/test_simple_task_runner.h"
-#include "chrome/browser/chromeos/settings/cros_settings.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chromeos/settings/cros_settings_names.h"
 #include "components/gcm_driver/fake_gcm_driver.h"
 #include "content/public/test/test_utils.h"
@@ -63,24 +61,11 @@ class HeartbeatSchedulerTest : public testing::Test {
   }
 
   void SetUp() override {
-    // Swap out the DeviceSettingsProvider with our stub settings provider
-    // so we can set values for the heartbeat frequency.
-    chromeos::CrosSettings* cros_settings = chromeos::CrosSettings::Get();
-    device_settings_provider_ =
-        cros_settings->GetProvider(chromeos::kReportDeviceVersionInfo);
-    EXPECT_TRUE(device_settings_provider_);
-    EXPECT_TRUE(
-        cros_settings->RemoveSettingsProvider(device_settings_provider_));
-    cros_settings->AddSettingsProvider(&stub_settings_provider_);
+    settings_helper_.ReplaceProvider(chromeos::kHeartbeatEnabled);
   }
 
   void TearDown() override {
     content::RunAllBlockingPoolTasksUntilIdle();
-    // Restore the real DeviceSettingsProvider.
-    chromeos::CrosSettings* cros_settings = chromeos::CrosSettings::Get();
-    EXPECT_TRUE(cros_settings->RemoveSettingsProvider(
-        &stub_settings_provider_));
-    cros_settings->AddSettingsProvider(device_settings_provider_);
   }
 
   void CheckPendingTaskDelay(base::Time last_heartbeat,
@@ -106,14 +91,8 @@ class HeartbeatSchedulerTest : public testing::Test {
   }
 
   base::MessageLoop loop_;
-
-  // Helpers used to mock out cros settings.
-  chromeos::ScopedTestDeviceSettingsService test_device_settings_service_;
-  chromeos::ScopedTestCrosSettings test_cros_settings_;
-  chromeos::CrosSettingsProvider* device_settings_provider_;
-  chromeos::StubCrosSettingsProvider stub_settings_provider_;
-
   MockGCMDriver gcm_driver_;
+  chromeos::ScopedCrosSettingsTestHelper settings_helper_;
 
   // TaskRunner used to run individual tests.
   scoped_refptr<base::TestSimpleTaskRunner> task_runner_;
@@ -125,16 +104,14 @@ class HeartbeatSchedulerTest : public testing::Test {
 TEST_F(HeartbeatSchedulerTest, Basic) {
   // Just makes sure we can spin up and shutdown the scheduler with
   // heartbeats disabled.
-  chromeos::CrosSettings::Get()->SetBoolean(
-      chromeos::kHeartbeatEnabled, false);
+  settings_helper_.SetBoolean(chromeos::kHeartbeatEnabled, false);
   ASSERT_TRUE(task_runner_->GetPendingTasks().empty());
 }
 
 TEST_F(HeartbeatSchedulerTest, PermanentlyFailedGCMRegistration) {
   // If heartbeats are enabled, we should register with GCMDriver.
   EXPECT_CALL(gcm_driver_, RegisterImpl(kHeartbeatGCMAppID, _));
-  chromeos::CrosSettings::Get()->SetBoolean(
-      chromeos::kHeartbeatEnabled, true);
+  settings_helper_.SetBoolean(chromeos::kHeartbeatEnabled, true);
   gcm_driver_.CompleteRegistration(
       kHeartbeatGCMAppID, gcm::GCMClient::GCM_DISABLED);
 
@@ -144,8 +121,7 @@ TEST_F(HeartbeatSchedulerTest, PermanentlyFailedGCMRegistration) {
 
 TEST_F(HeartbeatSchedulerTest, TemporarilyFailedGCMRegistration) {
   EXPECT_CALL(gcm_driver_, RegisterImpl(kHeartbeatGCMAppID, _));
-  chromeos::CrosSettings::Get()->SetBoolean(
-      chromeos::kHeartbeatEnabled, true);
+  settings_helper_.SetBoolean(chromeos::kHeartbeatEnabled, true);
   gcm_driver_.CompleteRegistration(
       kHeartbeatGCMAppID, gcm::GCMClient::SERVER_ERROR);
   testing::Mock::VerifyAndClearExpectations(&gcm_driver_);
@@ -165,8 +141,7 @@ TEST_F(HeartbeatSchedulerTest, TemporarilyFailedGCMRegistration) {
 
 TEST_F(HeartbeatSchedulerTest, ChangeHeartbeatFrequency) {
   EXPECT_CALL(gcm_driver_, RegisterImpl(kHeartbeatGCMAppID, _));
-  chromeos::CrosSettings::Get()->SetBoolean(
-      chromeos::kHeartbeatEnabled, true);
+  settings_helper_.SetBoolean(chromeos::kHeartbeatEnabled, true);
   gcm_driver_.CompleteRegistration(
       kHeartbeatGCMAppID, gcm::GCMClient::SUCCESS);
 
@@ -176,8 +151,7 @@ TEST_F(HeartbeatSchedulerTest, ChangeHeartbeatFrequency) {
   testing::Mock::VerifyAndClearExpectations(&gcm_driver_);
 
   const int new_delay = 1234*1000;  // 1234 seconds.
-  chromeos::CrosSettings::Get()->SetInteger(chromeos::kHeartbeatFrequency,
-                                            new_delay);
+  settings_helper_.SetInteger(chromeos::kHeartbeatFrequency, new_delay);
   // Now run pending heartbeat task, should send a heartbeat.
   gcm::GCMClient::OutgoingMessage message;
   EXPECT_CALL(gcm_driver_, SendImpl(kHeartbeatGCMAppID, _, _))
@@ -197,8 +171,7 @@ TEST_F(HeartbeatSchedulerTest, ChangeHeartbeatFrequency) {
 TEST_F(HeartbeatSchedulerTest, DisableHeartbeats) {
   // Makes sure that we can disable heartbeats on the fly.
   EXPECT_CALL(gcm_driver_, RegisterImpl(kHeartbeatGCMAppID, _));
-  chromeos::CrosSettings::Get()->SetBoolean(
-      chromeos::kHeartbeatEnabled, true);
+  settings_helper_.SetBoolean(chromeos::kHeartbeatEnabled, true);
   gcm::GCMClient::OutgoingMessage message;
   EXPECT_CALL(gcm_driver_, SendImpl(kHeartbeatGCMAppID, _, _))
       .WillOnce(SaveArg<2>(&message));
@@ -221,8 +194,7 @@ TEST_F(HeartbeatSchedulerTest, DisableHeartbeats) {
   testing::Mock::VerifyAndClearExpectations(&gcm_driver_);
 
   // Now disable heartbeats. Should get no more heartbeats sent.
-  chromeos::CrosSettings::Get()->SetBoolean(
-      chromeos::kHeartbeatEnabled, false);
+  settings_helper_.SetBoolean(chromeos::kHeartbeatEnabled, false);
   task_runner_->RunPendingTasks();
   EXPECT_TRUE(task_runner_->GetPendingTasks().empty());
 }
@@ -232,8 +204,7 @@ TEST_F(HeartbeatSchedulerTest, CheckMessageContents) {
   EXPECT_CALL(gcm_driver_, RegisterImpl(kHeartbeatGCMAppID, _));
   EXPECT_CALL(gcm_driver_, SendImpl(kHeartbeatGCMAppID, _, _))
       .WillOnce(SaveArg<2>(&message));
-  chromeos::CrosSettings::Get()->SetBoolean(
-      chromeos::kHeartbeatEnabled, true);
+  settings_helper_.SetBoolean(chromeos::kHeartbeatEnabled, true);
   gcm_driver_.CompleteRegistration(
       kHeartbeatGCMAppID, gcm::GCMClient::SUCCESS);
   task_runner_->RunPendingTasks();
diff --git a/chrome/browser/chromeos/policy/network_configuration_updater_unittest.cc b/chrome/browser/chromeos/policy/network_configuration_updater_unittest.cc
index 1dd6406..da4a95c 100644
--- a/chrome/browser/chromeos/policy/network_configuration_updater_unittest.cc
+++ b/chrome/browser/chromeos/policy/network_configuration_updater_unittest.cc
@@ -12,8 +12,7 @@
 #include "chrome/browser/chromeos/policy/device_network_configuration_updater.h"
 #include "chrome/browser/chromeos/policy/user_network_configuration_updater.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chrome/test/base/testing_profile.h"
 #include "chromeos/network/fake_network_device_handler.h"
 #include "chromeos/network/mock_managed_network_configuration_handler.h"
@@ -287,10 +286,7 @@ class NetworkConfigurationUpdaterTest : public testing::Test {
   StrictMock<chromeos::MockManagedNetworkConfigurationHandler>
       network_config_handler_;
   FakeNetworkDeviceHandler network_device_handler_;
-
-  // Not used directly. Required for CrosSettings.
-  chromeos::ScopedTestDeviceSettingsService scoped_device_settings_service_;
-  chromeos::ScopedTestCrosSettings scoped_cros_settings_;
+  chromeos::ScopedCrosSettingsTestHelper settings_helper_;
 
   // Ownership of certificate_importer_owned_ is passed to the
   // NetworkConfigurationUpdater. When that happens, |certificate_importer_|
@@ -313,28 +309,16 @@ TEST_F(NetworkConfigurationUpdaterTest, CellularAllowRoaming) {
   // Ignore network config updates.
   EXPECT_CALL(network_config_handler_, SetPolicy(_, _, _, _)).Times(AtLeast(1));
 
-  // Setup the DataRoaming device setting.
-  chromeos::CrosSettings* cros_settings = chromeos::CrosSettings::Get();
-  chromeos::CrosSettingsProvider* device_settings_provider =
-      cros_settings->GetProvider(chromeos::kSignedDataRoamingEnabled);
-  cros_settings->RemoveSettingsProvider(device_settings_provider);
-  delete device_settings_provider;
-  chromeos::StubCrosSettingsProvider* stub_settings_provider =
-      new chromeos::StubCrosSettingsProvider;
-  cros_settings->AddSettingsProvider(stub_settings_provider);
-
-  chromeos::CrosSettings::Get()->Set(chromeos::kSignedDataRoamingEnabled,
-                                     base::FundamentalValue(false));
+  settings_helper_.ReplaceProvider(chromeos::kSignedDataRoamingEnabled);
+  settings_helper_.SetBoolean(chromeos::kSignedDataRoamingEnabled, false);
   EXPECT_FALSE(network_device_handler_.allow_roaming_);
 
   CreateNetworkConfigurationUpdaterForDevicePolicy();
   MarkPolicyProviderInitialized();
-  chromeos::CrosSettings::Get()->Set(chromeos::kSignedDataRoamingEnabled,
-                                     base::FundamentalValue(true));
+  settings_helper_.SetBoolean(chromeos::kSignedDataRoamingEnabled, true);
   EXPECT_TRUE(network_device_handler_.allow_roaming_);
 
-  chromeos::CrosSettings::Get()->Set(chromeos::kSignedDataRoamingEnabled,
-                                     base::FundamentalValue(false));
+  settings_helper_.SetBoolean(chromeos::kSignedDataRoamingEnabled, false);
   EXPECT_FALSE(network_device_handler_.allow_roaming_);
 }
 
diff --git a/chrome/browser/chromeos/policy/status_uploader_unittest.cc b/chrome/browser/chromeos/policy/status_uploader_unittest.cc
index 4ef34eb..13a033c 100644
--- a/chrome/browser/chromeos/policy/status_uploader_unittest.cc
+++ b/chrome/browser/chromeos/policy/status_uploader_unittest.cc
@@ -7,8 +7,7 @@
 #include "base/time/time.h"
 #include "chrome/browser/chromeos/policy/device_status_collector.h"
 #include "chrome/browser/chromeos/policy/status_uploader.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chromeos/settings/cros_settings_names.h"
 #include "components/policy/core/common/cloud/cloud_policy_client.h"
 #include "components/policy/core/common/cloud/mock_cloud_policy_client.h"
@@ -46,35 +45,18 @@ class MockDeviceStatusCollector : public policy::DeviceStatusCollector {
 namespace policy {
 class StatusUploaderTest : public testing::Test {
  public:
-  StatusUploaderTest()
-      : task_runner_(new base::TestSimpleTaskRunner()),
-        device_settings_provider_(nullptr) {
+  StatusUploaderTest() : task_runner_(new base::TestSimpleTaskRunner()) {
     DeviceStatusCollector::RegisterPrefs(prefs_.registry());
   }
 
   void SetUp() override {
     client_.SetDMToken("dm_token");
     collector_.reset(new MockDeviceStatusCollector(&prefs_));
-
-    // Swap out the DeviceSettingsProvider with our stub settings provider
-    // so we can set values for the upload frequency.
-    chromeos::CrosSettings* cros_settings = chromeos::CrosSettings::Get();
-    device_settings_provider_ =
-        cros_settings->GetProvider(chromeos::kReportDeviceVersionInfo);
-    EXPECT_TRUE(device_settings_provider_);
-    EXPECT_TRUE(
-        cros_settings->RemoveSettingsProvider(device_settings_provider_));
-    cros_settings->AddSettingsProvider(&stub_settings_provider_);
-
+    settings_helper_.ReplaceProvider(chromeos::kReportUploadFrequency);
   }
 
   void TearDown() override {
     content::RunAllBlockingPoolTasksUntilIdle();
-    // Restore the real DeviceSettingsProvider.
-    chromeos::CrosSettings* cros_settings = chromeos::CrosSettings::Get();
-    EXPECT_TRUE(cros_settings->RemoveSettingsProvider(
-        &stub_settings_provider_));
-    cros_settings->AddSettingsProvider(device_settings_provider_);
   }
 
   // Given a pending task to upload status, mocks out a server response.
@@ -114,11 +96,8 @@ class StatusUploaderTest : public testing::Test {
 
   base::MessageLoop loop_;
   scoped_refptr<base::TestSimpleTaskRunner> task_runner_;
-  chromeos::ScopedTestDeviceSettingsService test_device_settings_service_;
-  chromeos::ScopedTestCrosSettings test_cros_settings_;
+  chromeos::ScopedCrosSettingsTestHelper settings_helper_;
   scoped_ptr<MockDeviceStatusCollector> collector_;
-  chromeos::CrosSettingsProvider* device_settings_provider_;
-  chromeos::StubCrosSettingsProvider stub_settings_provider_;
   MockCloudPolicyClient client_;
   MockDeviceManagementService device_management_service_;
   TestingPrefServiceSimple prefs_;
@@ -137,8 +116,7 @@ TEST_F(StatusUploaderTest, DifferentFrequencyAtStart) {
   // when it is passed to the StatusUploader constructor below.
   MockDeviceStatusCollector* const mock_collector = collector_.get();
   const int new_delay = StatusUploader::kDefaultUploadDelayMs * 2;
-  chromeos::CrosSettings::Get()->SetInteger(chromeos::kReportUploadFrequency,
-                                            new_delay);
+  settings_helper_.SetInteger(chromeos::kReportUploadFrequency, new_delay);
   const base::TimeDelta expected_delay = base::TimeDelta::FromMilliseconds(
       new_delay);
   EXPECT_TRUE(task_runner_->GetPendingTasks().empty());
@@ -202,8 +180,7 @@ TEST_F(StatusUploaderTest, ChangeFrequency) {
   // Change the frequency. The new frequency should be reflected in the timing
   // used for the next callback.
   const int new_delay = StatusUploader::kDefaultUploadDelayMs * 2;
-  chromeos::CrosSettings::Get()->SetInteger(chromeos::kReportUploadFrequency,
-                                            new_delay);
+  settings_helper_.SetInteger(chromeos::kReportUploadFrequency, new_delay);
   const base::TimeDelta expected_delay = base::TimeDelta::FromMilliseconds(
       new_delay);
   RunPendingUploadTaskAndCheckNext(uploader, expected_delay);
diff --git a/chrome/browser/chromeos/settings/device_settings_provider.cc b/chrome/browser/chromeos/settings/device_settings_provider.cc
index a33b23f..05fe7685 100644
--- a/chrome/browser/chromeos/settings/device_settings_provider.cc
+++ b/chrome/browser/chromeos/settings/device_settings_provider.cc
@@ -56,10 +56,14 @@ const char* const kKnownSettings[] = {
     kAllowedConnectionTypesForUpdate,
     kAttestationForContentProtectionEnabled,
     kDeviceAttestationEnabled,
+    kDeviceDisabled,
+    kDeviceDisabledMessage,
     kDeviceOwner,
+    kExtensionCacheSize,
     kHeartbeatEnabled,
     kHeartbeatFrequency,
     kPolicyMissingMitigationMode,
+    kRebootOnShutdown,
     kReleaseChannel,
     kReleaseChannelDelegated,
     kReportDeviceActivityTimes,
@@ -79,10 +83,6 @@ const char* const kKnownSettings[] = {
     kSystemUse24HourClock,
     kUpdateDisabled,
     kVariationsRestrictParameter,
-    kDeviceDisabled,
-    kDeviceDisabledMessage,
-    kRebootOnShutdown,
-    kExtensionCacheSize,
 };
 
 bool HasOldMetricsFile() {
diff --git a/chrome/browser/chromeos/settings/device_settings_test_helper.h b/chrome/browser/chromeos/settings/device_settings_test_helper.h
index 0e5742e..0736342 100644
--- a/chrome/browser/chromeos/settings/device_settings_test_helper.h
+++ b/chrome/browser/chromeos/settings/device_settings_test_helper.h
@@ -19,7 +19,6 @@
 #include "chrome/browser/chromeos/login/users/scoped_user_manager_enabler.h"
 #include "chrome/browser/chromeos/policy/device_policy_builder.h"
 #include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chrome/browser/chromeos/settings/device_settings_test_helper.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "components/ownership/mock_owner_key_util.h"
 #include "content/public/test/test_browser_thread_bundle.h"
diff --git a/chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.cc b/chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.cc
new file mode 100644
index 0000000..bcbb947
--- /dev/null
+++ b/chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.cc
@@ -0,0 +1,132 @@
+// Copyright (c) 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 "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
+
+#include "base/logging.h"
+#include "base/values.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/chromeos/ownership/fake_owner_settings_service.h"
+#include "chrome/browser/chromeos/ownership/owner_settings_service_chromeos.h"
+#include "chrome/browser/chromeos/policy/proto/chrome_device_policy.pb.h"
+#include "chrome/browser/chromeos/settings/cros_settings.h"
+#include "chrome/browser/chromeos/settings/device_settings_cache.h"
+#include "chrome/browser/chromeos/settings/device_settings_service.h"
+#include "chrome/browser/profiles/profile.h"
+#include "components/ownership/mock_owner_key_util.h"
+#include "policy/proto/device_management_backend.pb.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chromeos {
+
+ScopedCrosSettingsTestHelper::ScopedCrosSettingsTestHelper() {
+  Initialize(true);
+}
+
+ScopedCrosSettingsTestHelper::ScopedCrosSettingsTestHelper(
+    bool create_settings_service) {
+  Initialize(create_settings_service);
+}
+
+ScopedCrosSettingsTestHelper::~ScopedCrosSettingsTestHelper() {
+  RestoreProvider();
+}
+
+scoped_ptr<FakeOwnerSettingsService>
+ScopedCrosSettingsTestHelper::CreateOwnerSettingsService(Profile* profile) {
+  return make_scoped_ptr(new FakeOwnerSettingsService(
+      profile, new ownership::MockOwnerKeyUtil(), &stub_settings_provider_));
+}
+
+void ScopedCrosSettingsTestHelper::ReplaceProvider(const std::string& path) {
+  CHECK(!real_settings_provider_);
+  // Swap out the DeviceSettingsProvider with our settings provider so we can
+  // set values for the specified path.
+  CrosSettings* const cros_settings = CrosSettings::Get();
+  real_settings_provider_ = cros_settings->GetProvider(path);
+  EXPECT_TRUE(real_settings_provider_);
+  EXPECT_TRUE(cros_settings->RemoveSettingsProvider(real_settings_provider_));
+  cros_settings->AddSettingsProvider(&stub_settings_provider_);
+}
+
+void ScopedCrosSettingsTestHelper::RestoreProvider() {
+  if (real_settings_provider_) {
+    // Restore the real DeviceSettingsProvider.
+    CrosSettings* const cros_settings = CrosSettings::Get();
+    EXPECT_TRUE(
+        cros_settings->RemoveSettingsProvider(&stub_settings_provider_));
+    cros_settings->AddSettingsProvider(real_settings_provider_);
+    real_settings_provider_ = nullptr;
+  }
+}
+
+void ScopedCrosSettingsTestHelper::SetTrustedStatus(
+    CrosSettingsProvider::TrustedStatus status) {
+  stub_settings_provider_.SetTrustedStatus(status);
+}
+
+void ScopedCrosSettingsTestHelper::SetCurrentUserIsOwner(bool owner) {
+  stub_settings_provider_.SetCurrentUserIsOwner(owner);
+}
+
+void ScopedCrosSettingsTestHelper::Set(const std::string& path,
+                                       const base::Value& in_value) {
+  stub_settings_provider_.Set(path, in_value);
+}
+
+void ScopedCrosSettingsTestHelper::SetBoolean(const std::string& path,
+                                              bool in_value) {
+  Set(path, base::FundamentalValue(in_value));
+}
+
+void ScopedCrosSettingsTestHelper::SetInteger(const std::string& path,
+                                              int in_value) {
+  Set(path, base::FundamentalValue(in_value));
+}
+
+void ScopedCrosSettingsTestHelper::SetDouble(const std::string& path,
+                                             double in_value) {
+  Set(path, base::FundamentalValue(in_value));
+}
+
+void ScopedCrosSettingsTestHelper::SetString(const std::string& path,
+                                             const std::string& in_value) {
+  Set(path, base::StringValue(in_value));
+}
+
+void ScopedCrosSettingsTestHelper::StoreCachedDeviceSetting(
+    const std::string& path) {
+  const base::Value* const value = stub_settings_provider_.Get(path);
+  if (value) {
+    enterprise_management::PolicyData data;
+    enterprise_management::ChromeDeviceSettingsProto settings;
+    if (device_settings_cache::Retrieve(&data,
+                                        g_browser_process->local_state())) {
+      CHECK(settings.ParseFromString(data.policy_value()));
+    }
+    OwnerSettingsServiceChromeOS::UpdateDeviceSettings(path, *value, settings);
+    CHECK(settings.SerializeToString(data.mutable_policy_value()));
+    CHECK(device_settings_cache::Store(data, g_browser_process->local_state()));
+  }
+}
+
+void ScopedCrosSettingsTestHelper::CopyStoredValue(const std::string& path) {
+  CrosSettingsProvider* provider = real_settings_provider_
+                                       ? real_settings_provider_
+                                       : CrosSettings::Get()->GetProvider(path);
+  const base::Value* const value = provider->Get(path);
+  if (value) {
+    stub_settings_provider_.Set(path, *value);
+  }
+}
+
+void ScopedCrosSettingsTestHelper::Initialize(bool create_settings_service) {
+  if (create_settings_service) {
+    CHECK(!DeviceSettingsService::IsInitialized());
+    test_device_settings_service_.reset(new ScopedTestDeviceSettingsService());
+    test_cros_settings_.reset(new ScopedTestCrosSettings());
+  }
+}
+
+}  // namespace chromeos
diff --git a/chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h b/chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h
new file mode 100644
index 0000000..86a07bd
--- /dev/null
+++ b/chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h
@@ -0,0 +1,83 @@
+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_SETTINGS_SCOPED_CROS_SETTINGS_TEST_HELPER_H_
+#define CHROME_BROWSER_CHROMEOS_SETTINGS_SCOPED_CROS_SETTINGS_TEST_HELPER_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chromeos/settings/cros_settings_provider.h"
+
+class Profile;
+
+namespace base {
+class Value;
+}
+
+namespace chromeos {
+
+class FakeOwnerSettingsService;
+class ScopedTestCrosSettings;
+class ScopedTestDeviceSettingsService;
+
+class ScopedCrosSettingsTestHelper {
+ public:
+  ScopedCrosSettingsTestHelper();
+
+  // In some cases it is required to pass |create_settings_service| as false:
+  // If the test already has a device settings service and/or CrosSettings set
+  // up by another (instantiated or base) class, creating another one causes
+  // crash.
+  explicit ScopedCrosSettingsTestHelper(bool create_settings_service);
+  ~ScopedCrosSettingsTestHelper();
+
+  // Methods to replace and restore CrosSettingsProvider for the specified
+  // |path|.
+  void ReplaceProvider(const std::string& path);
+  void RestoreProvider();
+
+  // Method to create an owner settings service that uses
+  // |stub_settings_provider_| as settings write path.
+  scoped_ptr<FakeOwnerSettingsService> CreateOwnerSettingsService(
+      Profile* profile);
+
+  // These methods simply call the according |stub_settings_provider_| method.
+  void SetTrustedStatus(CrosSettingsProvider::TrustedStatus status);
+  void SetCurrentUserIsOwner(bool owner);
+  void Set(const std::string& path, const base::Value& in_value);
+
+  // Convenience forms of Set() from CrosSettingsProvider. These methods will
+  // replace any existing value at that |path|, even if it has a different type.
+  void SetBoolean(const std::string& path, bool in_value);
+  void SetInteger(const std::string& path, int in_value);
+  void SetDouble(const std::string& path, double in_value);
+  void SetString(const std::string& path, const std::string& in_value);
+
+  // This may be called before |ReplaceProvider| to copy values currently stored
+  // in the old provider. If the method is called after |ReplaceProvider|, then
+  // the value is retreived from |real_settings_provider_| for any |path|.
+  void CopyStoredValue(const std::string& path);
+
+  // Write the setting from |path| to local state so that it can be retreived
+  // later on browser test startup by the device settings service.
+  void StoreCachedDeviceSetting(const std::string& path);
+
+ private:
+  // Helpers used to mock out cros settings.
+  scoped_ptr<ScopedTestDeviceSettingsService> test_device_settings_service_;
+  scoped_ptr<ScopedTestCrosSettings> test_cros_settings_;
+  CrosSettingsProvider* real_settings_provider_ = nullptr;
+  StubCrosSettingsProvider stub_settings_provider_;
+
+  void Initialize(bool create_settings_service);
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedCrosSettingsTestHelper);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_SETTINGS_SCOPED_CROS_SETTINGS_TEST_HELPER_H_
diff --git a/chrome/browser/chromeos/settings/shutdown_policy_handler_unittest.cc b/chrome/browser/chromeos/settings/shutdown_policy_handler_unittest.cc
index eadd410..8b9669f9 100644
--- a/chrome/browser/chromeos/settings/shutdown_policy_handler_unittest.cc
+++ b/chrome/browser/chromeos/settings/shutdown_policy_handler_unittest.cc
@@ -6,15 +6,10 @@
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
-#include "base/command_line.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/run_loop.h"
-#include "base/values.h"
-#include "chrome/browser/chromeos/settings/device_settings_service.h"
-#include "chromeos/chromeos_switches.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/settings/cros_settings_names.h"
-#include "chromeos/settings/cros_settings_provider.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -30,29 +25,21 @@ class ShutdownPolicyHandlerTest : public testing::Test,
 
  protected:
   ShutdownPolicyHandlerTest()
-      : cros_settings_(nullptr),
-        callback_called_(false),
+      : callback_called_(false),
         reboot_on_shutdown_(false),
-        delegate_invocations_count_(0) {
-    base::CommandLine::ForCurrentProcess()->AppendSwitch(
-        switches::kStubCrosSettings);
-    test_cros_settings_.reset(new ScopedTestCrosSettings);
-}
+        delegate_invocations_count_(0) {}
 
   // testing::Test:
-void SetUp() override {
+  void SetUp() override {
     testing::Test::SetUp();
-    cros_settings_ = CrosSettings::Get();
     DBusThreadManager::Initialize();
+    settings_helper_.ReplaceProvider(kRebootOnShutdown);
   }
 
   void TearDown() override { DBusThreadManager::Shutdown(); }
 
   void SetRebootOnShutdown(bool reboot_on_shutdown) {
-    const base::FundamentalValue reboot_on_shutdown_value(reboot_on_shutdown);
-    CrosSettings::Get()
-        ->GetProvider(kRebootOnShutdown)
-        ->Set(kRebootOnShutdown, reboot_on_shutdown_value);
+    settings_helper_.SetBoolean(kRebootOnShutdown, reboot_on_shutdown);
     base::RunLoop().RunUntilIdle();
   }
 
@@ -64,20 +51,14 @@ void SetUp() override {
 
  protected:
   content::TestBrowserThreadBundle thread_bundle_;
-
-  CrosSettings* cros_settings_;
-  scoped_ptr<CrosSettingsProvider> device_settings_provider_;
-
-  ScopedTestDeviceSettingsService test_device_settings_service_;
-  scoped_ptr<ScopedTestCrosSettings> test_cros_settings_;
-
+  ScopedCrosSettingsTestHelper settings_helper_;
   bool callback_called_;
   bool reboot_on_shutdown_;
   int delegate_invocations_count_;
 };
 
 TEST_F(ShutdownPolicyHandlerTest, RetrieveTrustedDevicePolicies) {
-  ShutdownPolicyHandler shutdown_policy_observer(cros_settings_, this);
+  ShutdownPolicyHandler shutdown_policy_observer(CrosSettings::Get(), this);
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(0, delegate_invocations_count_);
 
@@ -100,7 +81,7 @@ TEST_F(ShutdownPolicyHandlerTest, RetrieveTrustedDevicePolicies) {
 }
 
 TEST_F(ShutdownPolicyHandlerTest, CheckIfRebootOnShutdown) {
-  ShutdownPolicyHandler shutdown_policy_observer(cros_settings_, this);
+  ShutdownPolicyHandler shutdown_policy_observer(CrosSettings::Get(), this);
   base::RunLoop().RunUntilIdle();
 
   // Allow shutdown.
diff --git a/chrome/browser/chromeos/settings/stub_cros_settings_provider.cc b/chrome/browser/chromeos/settings/stub_cros_settings_provider.cc
index c11e3c3..3b6a89a 100644
--- a/chrome/browser/chromeos/settings/stub_cros_settings_provider.cc
+++ b/chrome/browser/chromeos/settings/stub_cros_settings_provider.cc
@@ -37,17 +37,27 @@ const base::Value* StubCrosSettingsProvider::Get(
 
 CrosSettingsProvider::TrustedStatus
     StubCrosSettingsProvider::PrepareTrustedValues(const base::Closure& cb) {
-  // We don't have a trusted store so all values are available immediately.
-  return TRUSTED;
+  return trusted_status_;
 }
 
 bool StubCrosSettingsProvider::HandlesSetting(const std::string& path) const {
   return DeviceSettingsProvider::IsDeviceSetting(path);
 }
 
+void StubCrosSettingsProvider::SetTrustedStatus(TrustedStatus status) {
+  trusted_status_ = status;
+}
+
+void StubCrosSettingsProvider::SetCurrentUserIsOwner(bool owner) {
+  current_user_is_owner_ = owner;
+}
+
 void StubCrosSettingsProvider::DoSet(const std::string& path,
                                      const base::Value& value) {
-  values_.SetValue(path, value.DeepCopy());
+  if (current_user_is_owner_)
+    values_.SetValue(path, value.DeepCopy());
+  else
+    LOG(WARNING) << "Changing settings from non-owner, setting=" << path;
   NotifyObservers(path);
 }
 
diff --git a/chrome/browser/chromeos/settings/stub_cros_settings_provider.h b/chrome/browser/chromeos/settings/stub_cros_settings_provider.h
index 5fcb65c1..4d54a3e 100644
--- a/chrome/browser/chromeos/settings/stub_cros_settings_provider.h
+++ b/chrome/browser/chromeos/settings/stub_cros_settings_provider.h
@@ -24,6 +24,9 @@ class StubCrosSettingsProvider : public CrosSettingsProvider {
   TrustedStatus PrepareTrustedValues(const base::Closure& callback) override;
   bool HandlesSetting(const std::string& path) const override;
 
+  void SetTrustedStatus(TrustedStatus status);
+  void SetCurrentUserIsOwner(bool owner);
+
  private:
   // CrosSettingsProvider implementation:
   void DoSet(const std::string& path, const base::Value& value) override;
@@ -34,6 +37,14 @@ class StubCrosSettingsProvider : public CrosSettingsProvider {
   // In-memory settings storage.
   PrefValueMap values_;
 
+  // Some tests imply that calling Set() as non-owner doesn't change the actual
+  // value but still trigger a notification. For such cases, it is possible to
+  // emulate this behavior by changing the ownership status to non-owner with
+  // |SetCurrentUserIsOwner(false)|.
+  bool current_user_is_owner_ = true;
+
+  TrustedStatus trusted_status_ = CrosSettingsProvider::TRUSTED;
+
   DISALLOW_COPY_AND_ASSIGN(StubCrosSettingsProvider);
 };
 
diff --git a/chrome/browser/extensions/api/enterprise_platform_keys_private/enterprise_platform_keys_private_api_unittest.cc b/chrome/browser/extensions/api/enterprise_platform_keys_private/enterprise_platform_keys_private_api_unittest.cc
index d85b6ad..3f64a3f 100644
--- a/chrome/browser/extensions/api/enterprise_platform_keys_private/enterprise_platform_keys_private_api_unittest.cc
+++ b/chrome/browser/extensions/api/enterprise_platform_keys_private/enterprise_platform_keys_private_api_unittest.cc
@@ -13,9 +13,10 @@
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "chrome/browser/chromeos/policy/stub_enterprise_install_attributes.h"
-#include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
+#include "chrome/browser/chromeos/settings/scoped_cros_settings_test_helper.h"
 #include "chrome/browser/extensions/extension_function_test_utils.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
+#include "chrome/browser/ui/browser.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/browser_with_test_window_test.h"
 #include "chromeos/attestation/attestation_constants.h"
@@ -24,7 +25,6 @@
 #include "chromeos/cryptohome/mock_async_method_caller.h"
 #include "chromeos/dbus/dbus_method_call_status.h"
 #include "chromeos/dbus/mock_cryptohome_client.h"
-#include "chromeos/settings/cros_settings_provider.h"
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "extensions/common/test_util.h"
@@ -141,7 +141,8 @@ void GetCertificateCallbackFalse(
 
 class EPKPChallengeKeyTestBase : public BrowserWithTestWindowTest {
  protected:
-  EPKPChallengeKeyTestBase() : extension_(test_util::CreateEmptyExtension()) {
+  EPKPChallengeKeyTestBase()
+      : settings_helper_(false), extension_(test_util::CreateEmptyExtension()) {
     // Set up the default behavior of mocks.
     ON_CALL(mock_cryptohome_client_, TpmAttestationDoesKeyExist(_, _, _, _))
         .WillByDefault(WithArgs<3>(Invoke(FakeBoolDBusMethod(
@@ -163,25 +164,8 @@ class EPKPChallengeKeyTestBase : public BrowserWithTestWindowTest {
     stub_install_attributes_.SetDeviceId("device_id");
     stub_install_attributes_.SetMode(policy::DEVICE_MODE_ENTERPRISE);
 
-    // Replace the default device setting provider with the stub.
-    device_settings_provider_ = chromeos::CrosSettings::Get()->GetProvider(
-        chromeos::kReportDeviceVersionInfo);
-    EXPECT_TRUE(device_settings_provider_ != NULL);
-    EXPECT_TRUE(chromeos::CrosSettings::Get()->
-                RemoveSettingsProvider(device_settings_provider_));
-    chromeos::CrosSettings::Get()->
-        AddSettingsProvider(&stub_settings_provider_);
-
-    // Set the device settings.
-    stub_settings_provider_.Set(chromeos::kDeviceAttestationEnabled,
-                                base::FundamentalValue(true));
-  }
-
-  virtual ~EPKPChallengeKeyTestBase() {
-    EXPECT_TRUE(chromeos::CrosSettings::Get()->
-                RemoveSettingsProvider(&stub_settings_provider_));
-    chromeos::CrosSettings::Get()->
-        AddSettingsProvider(device_settings_provider_);
+    settings_helper_.ReplaceProvider(chromeos::kDeviceAttestationEnabled);
+    settings_helper_.SetBoolean(chromeos::kDeviceAttestationEnabled, true);
   }
 
   virtual void SetUp() override {
@@ -206,10 +190,9 @@ class EPKPChallengeKeyTestBase : public BrowserWithTestWindowTest {
   NiceMock<chromeos::MockCryptohomeClient> mock_cryptohome_client_;
   NiceMock<cryptohome::MockAsyncMethodCaller> mock_async_method_caller_;
   NiceMock<chromeos::attestation::MockAttestationFlow> mock_attestation_flow_;
+  chromeos::ScopedCrosSettingsTestHelper settings_helper_;
   scoped_refptr<extensions::Extension> extension_;
   policy::StubEnterpriseInstallAttributes stub_install_attributes_;
-  chromeos::CrosSettingsProvider* device_settings_provider_;
-  chromeos::StubCrosSettingsProvider stub_settings_provider_;
   PrefService* prefs_;
 };
 
@@ -260,8 +243,7 @@ TEST_F(EPKPChallengeMachineKeyTest, ExtensionNotWhitelisted) {
 }
 
 TEST_F(EPKPChallengeMachineKeyTest, DevicePolicyDisabled) {
-  stub_settings_provider_.Set(chromeos::kDeviceAttestationEnabled,
-                              base::FundamentalValue(false));
+  settings_helper_.SetBoolean(chromeos::kDeviceAttestationEnabled, false);
 
   EXPECT_EQ(EPKPChallengeKeyBase::kDevicePolicyDisabledError,
             utils::RunFunctionAndReturnError(func_.get(), kArgs, browser()));
@@ -397,8 +379,7 @@ TEST_F(EPKPChallengeUserKeyTest, ExtensionNotWhitelisted) {
 }
 
 TEST_F(EPKPChallengeUserKeyTest, DevicePolicyDisabled) {
-  stub_settings_provider_.Set(chromeos::kDeviceAttestationEnabled,
-                              base::FundamentalValue(false));
+  settings_helper_.SetBoolean(chromeos::kDeviceAttestationEnabled, false);
 
   EXPECT_EQ(EPKPChallengeKeyBase::kDevicePolicyDisabledError,
             utils::RunFunctionAndReturnError(func_.get(), kArgs, browser()));
diff --git a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
index f3ef877..c70275f 100644
--- a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
@@ -58,6 +58,8 @@
 #include "chrome/browser/chromeos/login/users/chrome_user_manager.h"
 #include "chrome/browser/chromeos/login/users/supervised_user_manager.h"
 #include "chrome/browser/chromeos/options/network_config_view.h"
+#include "chrome/browser/chromeos/ownership/owner_settings_service_chromeos.h"
+#include "chrome/browser/chromeos/ownership/owner_settings_service_chromeos_factory.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos.h"
 #include "chrome/browser/chromeos/profiles/multiprofiles_intro_dialog.h"
@@ -1018,8 +1020,17 @@ void SystemTrayDelegateChromeOS::UpdateClockType() {
   GetSystemTrayNotifier()->NotifyDateFormatChanged();
   // This also works for enterprise-managed devices because they never have
   // local owner.
-  if (user_manager::UserManager::Get()->IsCurrentUserOwner())
-    CrosSettings::Get()->SetBoolean(kSystemUse24HourClock, use_24_hour_clock);
+  if (user_manager::UserManager::Get()->IsCurrentUserOwner()) {
+    user_manager::User* const user =
+        user_manager::UserManager::Get()->GetActiveUser();
+    CHECK(user);
+    Profile* const profile = ProfileHelper::Get()->GetProfileByUser(user);
+    CHECK(profile);
+    OwnerSettingsServiceChromeOS* const service =
+        OwnerSettingsServiceChromeOSFactory::GetForBrowserContext(profile);
+    CHECK(service);
+    service->SetBoolean(kSystemUse24HourClock, use_24_hour_clock);
+  }
 }
 
 void SystemTrayDelegateChromeOS::UpdateShowLogoutButtonInTray() {
@@ -1120,8 +1131,15 @@ void SystemTrayDelegateChromeOS::LoggedInStateChanged() {
   // user's profile has actually been loaded (http://crbug.com/317745). The
   // system tray's time format is updated at login via SetProfile().
   if (user_manager::UserManager::Get()->IsCurrentUserOwner()) {
-    CrosSettings::Get()->SetBoolean(kSystemUse24HourClock,
-                                    ShouldUse24HourClock());
+    user_manager::User* const user =
+        user_manager::UserManager::Get()->GetActiveUser();
+    CHECK(user);
+    Profile* const profile = ProfileHelper::Get()->GetProfileByUser(user);
+    CHECK(profile);
+    OwnerSettingsServiceChromeOS* const service =
+        OwnerSettingsServiceChromeOSFactory::GetForBrowserContext(profile);
+    CHECK(service);
+    service->SetBoolean(kSystemUse24HourClock, ShouldUse24HourClock());
   }
 }
 
diff --git a/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc b/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
index d8a0567..b1d3d56 100644
--- a/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
+++ b/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
@@ -15,6 +15,7 @@
 #include "base/strings/string_util.h"
 #include "base/sys_info.h"
 #include "base/values.h"
+#include "chrome/browser/chromeos/ownership/owner_settings_service_chromeos.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
@@ -94,11 +95,12 @@ bool ExtractsAppIdFromInput(const std::string& input,
 
 }  // namespace
 
-KioskAppsHandler::KioskAppsHandler()
+KioskAppsHandler::KioskAppsHandler(OwnerSettingsServiceChromeOS* service)
     : kiosk_app_manager_(KioskAppManager::Get()),
       initialized_(false),
       is_kiosk_enabled_(false),
       is_auto_launch_enabled_(false),
+      owner_settings_service_(service),
       weak_ptr_factory_(this) {
   kiosk_app_manager_->AddObserver(this);
 }
@@ -281,7 +283,7 @@ void KioskAppsHandler::HandleAddKioskApp(const base::ListValue* args) {
     return;
   }
 
-  kiosk_app_manager_->AddApp(app_id);
+  kiosk_app_manager_->AddApp(app_id, owner_settings_service_);
 }
 
 void KioskAppsHandler::HandleRemoveKioskApp(const base::ListValue* args) {
@@ -291,7 +293,7 @@ void KioskAppsHandler::HandleRemoveKioskApp(const base::ListValue* args) {
   std::string app_id;
   CHECK(args->GetString(0, &app_id));
 
-  kiosk_app_manager_->RemoveApp(app_id);
+  kiosk_app_manager_->RemoveApp(app_id, owner_settings_service_);
 }
 
 void KioskAppsHandler::HandleEnableKioskAutoLaunch(
@@ -302,7 +304,7 @@ void KioskAppsHandler::HandleEnableKioskAutoLaunch(
   std::string app_id;
   CHECK(args->GetString(0, &app_id));
 
-  kiosk_app_manager_->SetAutoLaunchApp(app_id);
+  kiosk_app_manager_->SetAutoLaunchApp(app_id, owner_settings_service_);
 }
 
 void KioskAppsHandler::HandleDisableKioskAutoLaunch(
@@ -317,7 +319,7 @@ void KioskAppsHandler::HandleDisableKioskAutoLaunch(
   if (startup_app_id != app_id)
     return;
 
-  kiosk_app_manager_->SetAutoLaunchApp("");
+  kiosk_app_manager_->SetAutoLaunchApp("", owner_settings_service_);
 }
 
 void KioskAppsHandler::HandleSetDisableBailoutShortcut(
@@ -328,7 +330,7 @@ void KioskAppsHandler::HandleSetDisableBailoutShortcut(
   bool disable_bailout_shortcut;
   CHECK(args->GetBoolean(0, &disable_bailout_shortcut));
 
-  CrosSettings::Get()->SetBoolean(
+  owner_settings_service_->SetBoolean(
       kAccountsPrefDeviceLocalAccountAutoLoginBailoutEnabled,
       !disable_bailout_shortcut);
 }
@@ -350,7 +352,7 @@ void KioskAppsHandler::ShowError(const std::string& app_id) {
   web_ui()->CallJavascriptFunction("extensions.KioskAppsOverlay.showError",
                                    app_id_value);
 
-  kiosk_app_manager_->RemoveApp(app_id);
+  kiosk_app_manager_->RemoveApp(app_id, owner_settings_service_);
 }
 
 }  // namespace chromeos
diff --git a/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.h b/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.h
index 23df3a1..83fa88e 100644
--- a/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.h
+++ b/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.h
@@ -25,11 +25,12 @@ class WebUIDataSource;
 namespace chromeos {
 
 class KioskAppManager;
+class OwnerSettingsServiceChromeOS;
 
 class KioskAppsHandler : public content::WebUIMessageHandler,
                          public KioskAppManagerObserver {
  public:
-  KioskAppsHandler();
+  explicit KioskAppsHandler(OwnerSettingsServiceChromeOS* service);
   ~KioskAppsHandler() override;
 
   void GetLocalizedValues(content::WebUIDataSource* source);
@@ -69,6 +70,7 @@ class KioskAppsHandler : public content::WebUIMessageHandler,
   bool initialized_;
   bool is_kiosk_enabled_;
   bool is_auto_launch_enabled_;
+  OwnerSettingsServiceChromeOS* const owner_settings_service_;  // not owned
   base::WeakPtrFactory<KioskAppsHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(KioskAppsHandler);
diff --git a/chrome/browser/ui/webui/extensions/extensions_ui.cc b/chrome/browser/ui/webui/extensions/extensions_ui.cc
index 49d921b..681fd3f 100644
--- a/chrome/browser/ui/webui/extensions/extensions_ui.cc
+++ b/chrome/browser/ui/webui/extensions/extensions_ui.cc
@@ -18,6 +18,7 @@
 #include "ui/base/resource/resource_bundle.h"
 
 #if defined(OS_CHROMEOS)
+#include "chrome/browser/chromeos/ownership/owner_settings_service_chromeos_factory.h"
 #include "chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.h"
 #endif
 
@@ -65,7 +66,9 @@ ExtensionsUI::ExtensionsUI(content::WebUI* web_ui) : WebUIController(web_ui) {
 
 #if defined(OS_CHROMEOS)
   chromeos::KioskAppsHandler* kiosk_app_handler =
-      new chromeos::KioskAppsHandler();
+      new chromeos::KioskAppsHandler(
+          chromeos::OwnerSettingsServiceChromeOSFactory::GetForBrowserContext(
+              profile));
   kiosk_app_handler->GetLocalizedValues(source);
   web_ui->AddMessageHandler(kiosk_app_handler);
 #endif
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index aafe8f5..fa9d5fa 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -727,6 +727,8 @@
       'browser/chromeos/login/wizard_controller_browsertest.cc',
       'browser/chromeos/memory/oom_priority_manager_browsertest.cc',
       'browser/chromeos/net/network_portal_detector_impl_browsertest.cc',
+      'browser/chromeos/ownership/fake_owner_settings_service.cc',
+      'browser/chromeos/ownership/fake_owner_settings_service.h',
       'browser/chromeos/policy/blocking_login_browsertest.cc',
       'browser/chromeos/policy/device_cloud_policy_browsertest.cc',
       'browser/chromeos/policy/device_local_account_browsertest.cc',
@@ -747,6 +749,8 @@
       'browser/chromeos/power/peripheral_battery_observer_browsertest.cc',
       'browser/chromeos/preferences_browsertest.cc',
       'browser/chromeos/profiles/profile_helper_browsertest.cc',
+      'browser/chromeos/settings/scoped_cros_settings_test_helper.cc',
+      'browser/chromeos/settings/scoped_cros_settings_test_helper.h',
       'browser/chromeos/shutdown_policy_browsertest.cc',
       'browser/chromeos/system/device_disabling_browsertest.cc',
       'browser/chromeos/system/tray_accessibility_browsertest.cc',
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index 62572cf..1897576 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -1301,6 +1301,8 @@
       'browser/chromeos/settings/device_oauth2_token_service_unittest.cc',
       'browser/chromeos/settings/device_settings_provider_unittest.cc',
       'browser/chromeos/settings/device_settings_service_unittest.cc',
+      'browser/chromeos/settings/scoped_cros_settings_test_helper.cc',
+      'browser/chromeos/settings/scoped_cros_settings_test_helper.h',
       'browser/chromeos/settings/session_manager_operation_unittest.cc',
       'browser/chromeos/settings/shutdown_policy_handler_unittest.cc',
       'browser/chromeos/settings/stub_cros_settings_provider_unittest.cc',