cros: Introduce LocalPolicyTestServerMixin

Used to setup and work with LocalPolicyTestServer.
Chrome OS tests are migrated.

TBD:
Enable disabled migrated tests
Migrate Chrome tests when mixins are Chrome-wide

Bug: 934224, 912704
Change-Id: I5fef3d20e3ec8dd23f6307139fab1fbc1517d3d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1495532
Commit-Queue: Roman Sorokin [CET] <rsorokin@chromium.org>
Reviewed-by: Pavol Marko <pmarko@chromium.org>
Reviewed-by: Yusuke Sato <yusukes@chromium.org>
Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638536}

chrome/browser/chromeos/arc/arc_session_manager_browsertest.cc

@@ -20,6 +20,7 @@
 #include "chrome/browser/chromeos/arc/arc_session_manager.h"
 #include "chrome/browser/chromeos/arc/arc_util.h"
 #include "chrome/browser/chromeos/arc/test/arc_data_removed_waiter.h"
+#include "chrome/browser/chromeos/login/test/local_policy_test_server_mixin.h"
 #include "chrome/browser/chromeos/login/users/fake_chrome_user_manager.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
@@ -28,7 +29,6 @@
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/policy/profile_policy_connector.h"
 #include "chrome/browser/policy/profile_policy_connector_factory.h"
-#include "chrome/browser/policy/test/local_policy_test_server.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/signin/identity_test_environment_profile_adaptor.h"
 #include "chrome/test/base/in_process_browser_test.h"
@@ -100,31 +100,20 @@ class ArcPlayStoreDisabledWaiter : public ArcSessionManager::Observer {
   DISALLOW_COPY_AND_ASSIGN(ArcPlayStoreDisabledWaiter);
 };
 
-class ArcSessionManagerTest : public InProcessBrowserTest {
+class ArcSessionManagerTest : public chromeos::MixinBasedInProcessBrowserTest {
  protected:
   ArcSessionManagerTest() {}
 
-  // InProcessBrowserTest:
+  // MixinBasedInProcessBrowserTest:
   ~ArcSessionManagerTest() override {}
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
+    chromeos::MixinBasedInProcessBrowserTest::SetUpCommandLine(command_line);
     arc::SetArcAvailableCommandLineForTesting(command_line);
   }
 
-  void SetUpInProcessBrowserTestFixture() override {
-    // Start test device management server.
-    test_server_.reset(new policy::LocalPolicyTestServer());
-    ASSERT_TRUE(test_server_->Start());
-
-    // Specify device management server URL.
-    std::string url = test_server_->GetServiceURL().spec();
-    base::CommandLine* const command_line =
-        base::CommandLine::ForCurrentProcess();
-    command_line->AppendSwitchASCII(policy::switches::kDeviceManagementUrl,
-                                    url);
-  }
-
   void SetUpOnMainThread() override {
+    chromeos::MixinBasedInProcessBrowserTest::SetUpOnMainThread();
     user_manager_enabler_ = std::make_unique<user_manager::ScopedUserManager>(
         std::make_unique<chromeos::FakeChromeUserManager>());
     // Init ArcSessionManager for testing.
@@ -188,8 +177,8 @@ class ArcSessionManagerTest : public InProcessBrowserTest {
     profile_.reset();
     base::RunLoop().RunUntilIdle();
     user_manager_enabler_.reset();
-    test_server_.reset();
     chromeos::ProfileHelper::SetAlwaysReturnPrimaryUserForTesting(false);
+    chromeos::MixinBasedInProcessBrowserTest::TearDownOnMainThread();
   }
 
   chromeos::FakeChromeUserManager* GetFakeUserManager() const {
@@ -214,7 +203,7 @@ class ArcSessionManagerTest : public InProcessBrowserTest {
   }
 
  private:
-  std::unique_ptr<policy::LocalPolicyTestServer> test_server_;
+  chromeos::LocalPolicyTestServerMixin local_policy_mixin_{&mixin_host_};
   std::unique_ptr<user_manager::ScopedUserManager> user_manager_enabler_;
   std::unique_ptr<IdentityTestEnvironmentProfileAdaptor>
       identity_test_environment_adaptor_;

chrome/browser/chromeos/login/saml/saml_browsertest.cc

@@ -35,6 +35,7 @@
 #include "chrome/browser/chromeos/login/test/fake_gaia_mixin.h"
 #include "chrome/browser/chromeos/login/test/https_forwarder.h"
 #include "chrome/browser/chromeos/login/test/js_checker.h"
+#include "chrome/browser/chromeos/login/test/local_policy_test_server_mixin.h"
 #include "chrome/browser/chromeos/login/test/oobe_base_test.h"
 #include "chrome/browser/chromeos/login/test/oobe_screen_waiter.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host.h"
@@ -47,7 +48,6 @@
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/media/webrtc/media_capture_devices_dispatcher.h"
-#include "chrome/browser/policy/test/local_policy_test_server.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/signin/signin_utils.h"
 #include "chrome/common/chrome_constants.h"
@@ -157,7 +157,6 @@ constexpr char kRelayState[] = "RelayState";
 
 constexpr char kTestUserinfoToken[] = "fake-userinfo-token";
 constexpr char kTestRefreshToken[] = "fake-refresh-token";
-constexpr char kPolicy[] = "{\"managed_users\": [\"*\"]}";
 
 constexpr char kAffiliationID[] = "some-affiliation-id";
 
@@ -855,8 +854,6 @@ class SAMLEnrollmentTest : public SamlTest,
   ~SAMLEnrollmentTest() override;
 
   // SamlTest:
-  void SetUp() override;
-  void SetUpCommandLine(base::CommandLine* command_line) override;
   void SetUpOnMainThread() override;
   void StartSamlAndWaitForIdpPageLoad(const std::string& gaia_email) override;
 
@@ -869,7 +866,7 @@ class SAMLEnrollmentTest : public SamlTest,
   content::WebContents* GetEnrollmentContents();
 
  private:
-  std::unique_ptr<policy::LocalPolicyTestServer> test_server_;
+  LocalPolicyTestServerMixin local_policy_mixin_{&mixin_host_};
   base::ScopedTempDir temp_dir_;
 
   std::unique_ptr<base::RunLoop> run_loop_;
@@ -887,26 +884,6 @@ SAMLEnrollmentTest::SAMLEnrollmentTest() {
 
 SAMLEnrollmentTest::~SAMLEnrollmentTest() {}
 
-void SAMLEnrollmentTest::SetUp() {
-  ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
-  const base::FilePath policy_file =
-      temp_dir_.GetPath().AppendASCII("policy.json");
-  ASSERT_EQ(static_cast<int>(strlen(kPolicy)),
-            base::WriteFile(policy_file, kPolicy, strlen(kPolicy)));
-
-  test_server_.reset(new policy::LocalPolicyTestServer(policy_file));
-  ASSERT_TRUE(test_server_->Start());
-
-  SamlTest::SetUp();
-}
-
-void SAMLEnrollmentTest::SetUpCommandLine(base::CommandLine* command_line) {
-  command_line->AppendSwitchASCII(policy::switches::kDeviceManagementUrl,
-                                  test_server_->GetServiceURL().spec());
-
-  SamlTest::SetUpCommandLine(command_line);
-}
-
 void SAMLEnrollmentTest::SetUpOnMainThread() {
   FakeGaia::AccessTokenInfo token_info;
   token_info.token = kTestUserinfoToken;

chrome/browser/chromeos/login/test/local_policy_test_server_mixin.cc

+// Copyright 2019 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/login/test/local_policy_test_server_mixin.h"
+
+#include <utility>
+
+#include "components/policy/core/common/cloud/cloud_policy_constants.h"
+#include "components/policy/core/common/cloud/policy_builder.h"
+#include "components/policy/core/common/policy_switches.h"
+
+namespace chromeos {
+
+namespace {
+
+base::Value GetDefaultConfig() {
+  base::Value config(base::Value::Type::DICTIONARY);
+
+  base::Value managed_users(base::Value::Type::LIST);
+  managed_users.GetList().emplace_back("*");
+  config.SetKey("managed_users", std::move(managed_users));
+
+  return config;
+}
+
+}  // namespace
+
+LocalPolicyTestServerMixin::LocalPolicyTestServerMixin(
+    InProcessBrowserTestMixinHost* host)
+    : InProcessBrowserTestMixin(host) {
+  server_config_ = GetDefaultConfig();
+}
+
+void LocalPolicyTestServerMixin::SetUp() {
+  policy_test_server_ = std::make_unique<policy::LocalPolicyTestServer>();
+  policy_test_server_->SetConfig(server_config_);
+  policy_test_server_->RegisterClient(policy::PolicyBuilder::kFakeToken,
+                                      policy::PolicyBuilder::kFakeDeviceId,
+                                      {} /* state_keys */);
+
+  ASSERT_TRUE(policy_test_server_->SetSigningKeyAndSignature(
+      policy::PolicyBuilder::CreateTestSigningKey().get(),
+      policy::PolicyBuilder::GetTestSigningKeySignature()));
+
+  ASSERT_TRUE(policy_test_server_->Start());
+}
+
+void LocalPolicyTestServerMixin::SetUpCommandLine(
+    base::CommandLine* command_line) {
+  // Specify device management server URL.
+  command_line->AppendSwitchASCII(policy::switches::kDeviceManagementUrl,
+                                  policy_test_server_->GetServiceURL().spec());
+}
+
+bool LocalPolicyTestServerMixin::UpdateDevicePolicy(
+    const enterprise_management::ChromeDeviceSettingsProto& policy) {
+  DCHECK(policy_test_server_);
+  return policy_test_server_->UpdatePolicy(
+      policy::dm_protocol::kChromeDevicePolicyType,
+      std::string() /* entity_id */, policy.SerializeAsString());
+}
+
+LocalPolicyTestServerMixin::~LocalPolicyTestServerMixin() = default;
+
+}  // namespace chromeos

chrome/browser/chromeos/login/test/local_policy_test_server_mixin.h

+// Copyright 2019 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_LOGIN_TEST_LOCAL_POLICY_TEST_SERVER_MIXIN_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_TEST_LOCAL_POLICY_TEST_SERVER_MIXIN_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "base/values.h"
+#include "chrome/browser/chromeos/login/mixin_based_in_process_browser_test.h"
+#include "chrome/browser/policy/test/local_policy_test_server.h"
+#include "components/policy/proto/chrome_device_policy.pb.h"
+
+namespace chromeos {
+
+// This test mixin covers setting up LocalPolicyTestServer and adding a
+// command-line flag to use it. Please see SetUp function for default settings.
+// Server is started after SetUp execution.
+class LocalPolicyTestServerMixin : public InProcessBrowserTestMixin {
+ public:
+  explicit LocalPolicyTestServerMixin(InProcessBrowserTestMixinHost* host);
+  ~LocalPolicyTestServerMixin() override;
+
+  policy::LocalPolicyTestServer* server() { return policy_test_server_.get(); }
+
+  // InProcessBrowserTestMixin:
+  void SetUp() override;
+  void SetUpCommandLine(base::CommandLine* command_line) override;
+
+  bool UpdateDevicePolicy(
+      const enterprise_management::ChromeDeviceSettingsProto& policy);
+
+ private:
+  std::unique_ptr<policy::LocalPolicyTestServer> policy_test_server_;
+  base::Value server_config_;
+
+  DISALLOW_COPY_AND_ASSIGN(LocalPolicyTestServerMixin);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_TEST_LOCAL_POLICY_TEST_SERVER_MIXIN_H_

chrome/browser/chromeos/login/webview_login_browsertest.cc

@@ -21,6 +21,7 @@
 #include "chrome/browser/chromeos/login/signin_partition_manager.h"
 #include "chrome/browser/chromeos/login/test/fake_gaia_mixin.h"
 #include "chrome/browser/chromeos/login/test/js_checker.h"
+#include "chrome/browser/chromeos/login/test/local_policy_test_server_mixin.h"
 #include "chrome/browser/chromeos/login/test/oobe_base_test.h"
 #include "chrome/browser/chromeos/login/test/oobe_screen_waiter.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host.h"
@@ -30,7 +31,6 @@
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/chromeos/settings/scoped_testing_cros_settings.h"
 #include "chrome/browser/chromeos/settings/stub_cros_settings_provider.h"
-#include "chrome/browser/policy/test/local_policy_test_server.h"
 #include "chrome/browser/ui/login/login_handler.h"
 #include "chrome/browser/ui/webui/signin/signin_utils.h"
 #include "chromeos/constants/chromeos_switches.h"
@@ -842,16 +842,7 @@ class WebviewProxyAuthLoginTest : public WebviewLoginTest {
         .set_public_key_version(1);
     device_policy_test_helper_.device_policy()->Build();
 
-    // Start policy server. Use the DMToken and DeviceId from PolicyBuilder.
-    // These also used in |device_policy_test_helper_| and was passed to
-    // |fake_session_manager_client_| above, so the device will request policy
-    // with these identifiers.
-    policy_test_server_.RegisterClient(policy::PolicyBuilder::kFakeToken,
-                                       policy::PolicyBuilder::kFakeDeviceId,
-                                       {} /* state_keys */);
     UpdateServedPolicyFromDevicePolicyTestHelper();
-    ASSERT_TRUE(policy_test_server_.Start());
-
     WebviewLoginTest::SetUp();
   }
 
@@ -859,8 +850,6 @@ class WebviewProxyAuthLoginTest : public WebviewLoginTest {
     command_line->AppendSwitchASCII(
         ::switches::kProxyServer,
         auth_proxy_server_->host_port_pair().ToString());
-    command_line->AppendSwitchASCII(policy::switches::kDeviceManagementUrl,
-                                    policy_test_server_.GetServiceURL().spec());
     WebviewLoginTest::SetUpCommandLine(command_line);
   }
 
@@ -933,10 +922,7 @@ class WebviewProxyAuthLoginTest : public WebviewLoginTest {
   }
 
   void UpdateServedPolicyFromDevicePolicyTestHelper() {
-    policy_test_server_.UpdatePolicy(
-        policy::dm_protocol::kChromeDevicePolicyType,
-        std::string() /* entity_id */,
-        device_policy_builder()->payload().SerializeAsString());
+    local_policy_mixin_.UpdateDevicePolicy(device_policy_builder()->payload());
   }
 
   policy::DevicePolicyBuilder* device_policy_builder() {
@@ -956,7 +942,7 @@ class WebviewProxyAuthLoginTest : public WebviewLoginTest {
   // A proxy server which requires authentication using the 'Basic'
   // authentication method.
   std::unique_ptr<net::SpawnedTestServer> auth_proxy_server_;
-  policy::LocalPolicyTestServer policy_test_server_;
+  LocalPolicyTestServerMixin local_policy_mixin_{&mixin_host_};
   policy::DevicePolicyCrosTestHelper device_policy_test_helper_;
 
   // FakeDBusThreadManager uses FakeSessionManagerClient.

chrome/browser/chromeos/policy/device_cloud_policy_browsertest.cc

@@ -17,6 +17,7 @@
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_process_platform_part.h"
+#include "chrome/browser/chromeos/login/test/local_policy_test_server_mixin.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/policy/device_policy_builder.h"
@@ -25,7 +26,6 @@
 #include "chrome/browser/chromeos/settings/device_settings_service.h"
 #include "chrome/browser/extensions/chrome_test_extension_loader.h"
 #include "chrome/browser/extensions/extension_service.h"
-#include "chrome/browser/policy/test/local_policy_test_server.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/chrome_constants.h"
@@ -109,14 +109,9 @@ class KeyRotationDeviceCloudPolicyTest : public DevicePolicyCrosBrowserTest {
 
   void SetUp() override {
     UpdateBuiltTestPolicyValue(kTestPolicyValue);
-    StartPolicyTestServer();
     DevicePolicyCrosBrowserTest::SetUp();
-  }
-
-  void SetUpCommandLine(base::CommandLine* command_line) override {
-    DevicePolicyCrosBrowserTest::SetUpCommandLine(command_line);
-    command_line->AppendSwitchASCII(policy::switches::kDeviceManagementUrl,
-                                    policy_test_server_.GetServiceURL().spec());
+    local_policy_mixin_.server()->EnableAutomaticRotationOfSigningKeys();
+    UpdateServedTestPolicy();
   }
 
   void SetUpInProcessBrowserTestFixture() override {
@@ -149,9 +144,8 @@ class KeyRotationDeviceCloudPolicyTest : public DevicePolicyCrosBrowserTest {
   }
 
   void UpdateServedTestPolicy() {
-    EXPECT_TRUE(policy_test_server_.UpdatePolicy(
-        dm_protocol::kChromeDevicePolicyType, std::string() /* entity_id */,
-        device_policy()->payload().SerializeAsString()));
+    EXPECT_TRUE(
+        local_policy_mixin_.UpdateDevicePolicy(device_policy()->payload()));
   }
 
   int GetTestPolicyValue() {
@@ -182,15 +176,6 @@ class KeyRotationDeviceCloudPolicyTest : public DevicePolicyCrosBrowserTest {
   }
 
  private:
-  void StartPolicyTestServer() {
-    policy_test_server_.RegisterClient(PolicyBuilder::kFakeToken,
-                                       PolicyBuilder::kFakeDeviceId,
-                                       {} /* state_keys */);
-    UpdateServedTestPolicy();
-    policy_test_server_.EnableAutomaticRotationOfSigningKeys();
-    EXPECT_TRUE(policy_test_server_.Start());
-  }
-
   void SetFakeDevicePolicy() {
     device_policy()
         ->payload()
@@ -222,7 +207,7 @@ class KeyRotationDeviceCloudPolicyTest : public DevicePolicyCrosBrowserTest {
     }
   }
 
-  LocalPolicyTestServer policy_test_server_;
+  chromeos::LocalPolicyTestServerMixin local_policy_mixin_{&mixin_host_};
   std::unique_ptr<PolicyChangeRegistrar> policy_change_registrar_;
   int awaited_policy_value_ = -1;
   std::unique_ptr<base::RunLoop> policy_change_waiting_run_loop_;
@@ -286,7 +271,6 @@ class SigninExtensionsDeviceCloudPolicyBrowserTest
   ~SigninExtensionsDeviceCloudPolicyBrowserTest() override = default;
 
   void SetUp() override {
-    StartPolicyTestServer();
     ASSERT_TRUE(embedded_test_server()->InitializeAndListen());
     DevicePolicyCrosBrowserTest::SetUp();
   }
@@ -295,8 +279,6 @@ class SigninExtensionsDeviceCloudPolicyBrowserTest
     DevicePolicyCrosBrowserTest::SetUpCommandLine(command_line);
     command_line->AppendSwitch(chromeos::switches::kLoginManager);
     command_line->AppendSwitch(chromeos::switches::kForceLoginManagerInTests);
-    command_line->AppendSwitchASCII(policy::switches::kDeviceManagementUrl,
-                                    policy_test_server_.GetServiceURL().spec());
     // The test app has to be whitelisted for sign-in screen.
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID, kTestExtensionId);
@@ -308,10 +290,9 @@ class SigninExtensionsDeviceCloudPolicyBrowserTest
     MarkAsEnterpriseOwned();
     SetFakeDevicePolicy();
 
-    EXPECT_TRUE(policy_test_server_.UpdatePolicy(
-        dm_protocol::kChromeDevicePolicyType, std::string() /* entity_id */,
-        device_policy()->payload().SerializeAsString()));
-    EXPECT_TRUE(policy_test_server_.UpdatePolicy(
+    EXPECT_TRUE(
+        local_policy_mixin_.UpdateDevicePolicy(device_policy()->payload()));
+    EXPECT_TRUE(local_policy_mixin_.server()->UpdatePolicy(
         dm_protocol::kChromeSigninExtensionPolicyType, kTestExtensionId,
         BuildTestComponentPolicyPayload().SerializeAsString()));
   }
@@ -375,17 +356,6 @@ class SigninExtensionsDeviceCloudPolicyBrowserTest
     return response;
   }
 
-  void StartPolicyTestServer() {
-    std::unique_ptr<crypto::RSAPrivateKey> signing_key(
-        PolicyBuilder::CreateTestSigningKey());
-    EXPECT_TRUE(policy_test_server_.SetSigningKeyAndSignature(
-        signing_key.get(), PolicyBuilder::GetTestSigningKeySignature()));
-    policy_test_server_.RegisterClient(PolicyBuilder::kFakeToken,
-                                       PolicyBuilder::kFakeDeviceId,
-                                       {} /* state_keys */);
-    EXPECT_TRUE(policy_test_server_.Start());
-  }
-
   void SetFakeDevicePolicy() {
     device_policy()->policy_data().set_public_key_version(
         kFakePolicyPublicKeyVersion);
@@ -421,7 +391,7 @@ class SigninExtensionsDeviceCloudPolicyBrowserTest
     builder->Build();
   }
 
-  LocalPolicyTestServer policy_test_server_;
+  chromeos::LocalPolicyTestServerMixin local_policy_mixin_{&mixin_host_};
 
   DISALLOW_COPY_AND_ASSIGN(SigninExtensionsDeviceCloudPolicyBrowserTest);
 };

chrome/browser/chromeos/policy/device_local_account_browsertest.cc

@@ -48,6 +48,7 @@
 #include "chrome/browser/chromeos/login/session/user_session_manager.h"
 #include "chrome/browser/chromeos/login/session/user_session_manager_test_api.h"
 #include "chrome/browser/chromeos/login/signin_specifics.h"
+#include "chrome/browser/chromeos/login/test/local_policy_test_server_mixin.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host.h"
 #include "chrome/browser/chromeos/login/ui/webui_login_view.h"
 #include "chrome/browser/chromeos/login/users/avatar/user_image_manager.h"
@@ -71,7 +72,6 @@
 #include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/policy/profile_policy_connector.h"
 #include "chrome/browser/policy/profile_policy_connector_factory.h"
-#include "chrome/browser/policy/test/local_policy_test_server.h"
 #include "chrome/browser/prefs/session_startup_pref.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
@@ -456,17 +456,6 @@ class DeviceLocalAccountTest : public DevicePolicyCrosBrowserTest,
   ~DeviceLocalAccountTest() override {}
 
   void SetUp() override {
-    // Configure and start the test server.
-    std::unique_ptr<crypto::RSAPrivateKey> signing_key(
-        PolicyBuilder::CreateTestSigningKey());
-    ASSERT_TRUE(test_server_.SetSigningKeyAndSignature(
-        signing_key.get(), PolicyBuilder::GetTestSigningKeySignature()));
-    signing_key.reset();
-    test_server_.RegisterClient(PolicyBuilder::kFakeToken,
-                                PolicyBuilder::kFakeDeviceId,
-                                {} /* state_keys */);
-    ASSERT_TRUE(test_server_.Start());
-
     BrowserList::AddObserver(this);
 
     DevicePolicyCrosBrowserTest::SetUp();
@@ -477,8 +466,6 @@ class DeviceLocalAccountTest : public DevicePolicyCrosBrowserTest,
     command_line->AppendSwitch(chromeos::switches::kLoginManager);
     command_line->AppendSwitch(chromeos::switches::kForceLoginManagerInTests);
     command_line->AppendSwitchASCII(chromeos::switches::kLoginProfile, "user");
-    command_line->AppendSwitchASCII(policy::switches::kDeviceManagementUrl,
-                                    test_server_.GetServiceURL().spec());
   }
 
   void SetUpInProcessBrowserTestFixture() override {
@@ -539,6 +526,7 @@ class DeviceLocalAccountTest : public DevicePolicyCrosBrowserTest,
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::BindOnce(&chrome::AttemptExit));
     base::RunLoop().RunUntilIdle();
+    DevicePolicyCrosBrowserTest::TearDownOnMainThread();
   }
 
   void LocalStateChanged(user_manager::UserManager* user_manager) override {
@@ -586,7 +574,7 @@ class DeviceLocalAccountTest : public DevicePolicyCrosBrowserTest,
 
   void UploadDeviceLocalAccountPolicy() {
     BuildDeviceLocalAccountPolicy();
-    ASSERT_TRUE(test_server_.UpdatePolicy(
+    ASSERT_TRUE(local_policy_mixin_.server()->UpdatePolicy(
         dm_protocol::kChromePublicAccountPolicyType, kAccountId1,
         device_local_account_policy_.payload().SerializeAsString()));
   }
@@ -618,9 +606,7 @@ class DeviceLocalAccountTest : public DevicePolicyCrosBrowserTest,
     account->set_type(
         em::DeviceLocalAccountInfoProto::ACCOUNT_TYPE_PUBLIC_SESSION);
     RefreshDevicePolicy();
-    ASSERT_TRUE(test_server_.UpdatePolicy(dm_protocol::kChromeDevicePolicyType,
-                                          std::string(),
-                                          proto.SerializeAsString()));
+    ASSERT_TRUE(local_policy_mixin_.UpdateDevicePolicy(proto));
   }
 
   void SetManagedSessionsEnabled(bool managed_sessions_enabled) {
@@ -637,9 +623,7 @@ class DeviceLocalAccountTest : public DevicePolicyCrosBrowserTest,
     device_local_accounts->set_auto_login_id(kAccountId1);
     device_local_accounts->set_auto_login_delay(0);
     RefreshDevicePolicy();
-    ASSERT_TRUE(test_server_.UpdatePolicy(dm_protocol::kChromeDevicePolicyType,
-                                          std::string(),
-                                          proto.SerializeAsString()));
+    ASSERT_TRUE(local_policy_mixin_.UpdateDevicePolicy(proto));
   }
 
   void CheckPublicSessionPresent(const AccountId& account_id) {
@@ -801,7 +785,7 @@ class DeviceLocalAccountTest : public DevicePolicyCrosBrowserTest,
   std::unique_ptr<base::RunLoop> run_loop_;
 
   UserPolicyBuilder device_local_account_policy_;
-  LocalPolicyTestServer test_server_;
+  chromeos::LocalPolicyTestServerMixin local_policy_mixin_{&mixin_host_};
 
   content::WebContents* contents_;
 
@@ -1023,8 +1007,7 @@ IN_PROC_BROWSER_TEST_F(DeviceLocalAccountTest, AccountListChange) {
   account1->set_type(
       em::DeviceLocalAccountInfoProto::ACCOUNT_TYPE_PUBLIC_SESSION);
 
-  test_server_.UpdatePolicy(dm_protocol::kChromeDevicePolicyType, std::string(),
-                            policy.SerializeAsString());
+  local_policy_mixin_.UpdateDevicePolicy(policy);
   g_browser_process->policy_service()->RefreshPolicies(base::Closure());
 
   // Make sure the second device-local account disappears.
@@ -2295,7 +2278,7 @@ IN_PROC_BROWSER_TEST_F(DeviceLocalAccountTest, PolicyForExtensions) {
   // Note that the policy for the device-local account will be fetched before
   // the session is started, so the policy for the app must be installed before
   // the first device policy fetch.
-  ASSERT_TRUE(test_server_.UpdatePolicyData(
+  ASSERT_TRUE(local_policy_mixin_.server()->UpdatePolicyData(
       dm_protocol::kChromeExtensionPolicyType, kShowManagedStorageID,
       "{"
       "  \"string\": {"
@@ -2343,7 +2326,7 @@ IN_PROC_BROWSER_TEST_F(DeviceLocalAccountTest, PolicyForExtensions) {
             *policy_service->GetPolicies(ns).GetValue("string"));
 
   // Now update the policy at the server.
-  ASSERT_TRUE(test_server_.UpdatePolicyData(
+  ASSERT_TRUE(local_policy_mixin_.server()->UpdatePolicyData(
       dm_protocol::kChromeExtensionPolicyType, kShowManagedStorageID,
       "{"
       "  \"string\": {"

chrome/browser/chromeos/policy/device_policy_cros_browser_test.cc

@@ -96,7 +96,7 @@ void DevicePolicyCrosBrowserTest::SetUp() {
   std::vector<std::string> state_keys;
   state_keys.push_back("1");
   fake_session_manager_client_->set_server_backed_state_keys(state_keys);
-  InProcessBrowserTest::SetUp();
+  chromeos::MixinBasedInProcessBrowserTest::SetUp();
 }
 
 void DevicePolicyCrosBrowserTest::SetUpInProcessBrowserTestFixture() {
@@ -106,6 +106,7 @@ void DevicePolicyCrosBrowserTest::SetUpInProcessBrowserTestFixture() {
   dbus_setter_->SetSessionManagerClient(
       std::unique_ptr<chromeos::SessionManagerClient>(
           fake_session_manager_client_));
+  chromeos::MixinBasedInProcessBrowserTest::SetUpInProcessBrowserTestFixture();
 }
 
 void DevicePolicyCrosBrowserTest::MarkOwnership() {

chrome/browser/chromeos/policy/device_policy_cros_browser_test.h

@@ -9,8 +9,8 @@
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "chrome/browser/chromeos/login/mixin_based_in_process_browser_test.h"
 #include "chrome/browser/chromeos/policy/device_policy_builder.h"
-#include "chrome/test/base/in_process_browser_test.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 
 namespace chromeos {
@@ -47,11 +47,13 @@ class DevicePolicyCrosTestHelper {
 };
 
 // Used to test Device policy changes in Chrome OS.
-class DevicePolicyCrosBrowserTest : public InProcessBrowserTest {
+class DevicePolicyCrosBrowserTest
+    : public chromeos::MixinBasedInProcessBrowserTest {
  protected:
   DevicePolicyCrosBrowserTest();
   ~DevicePolicyCrosBrowserTest() override;
 
+  // MixinBasedInProcessBrowserTest:
   void SetUp() override;
   void SetUpInProcessBrowserTestFixture() override;
 

chrome/browser/chromeos/policy/user_network_configuration_updater_factory_browsertest.cc

@@ -15,6 +15,7 @@
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/login/existing_user_controller.h"
 #include "chrome/browser/chromeos/login/screens/gaia_view.h"
+#include "chrome/browser/chromeos/login/test/local_policy_test_server_mixin.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 #include "chrome/browser/chromeos/policy/device_policy_cros_browser_test.h"
@@ -23,7 +24,6 @@
 #include "chrome/browser/chromeos/policy/user_network_configuration_updater_factory.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/net/nss_context.h"
-#include "chrome/browser/policy/test/local_policy_test_server.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
@@ -437,21 +437,6 @@ class PolicyProvidedTrustAnchorsDeviceLocalAccountTest
   }
 
  protected:
-  void SetUp() override {
-    // Configure and start the test server.
-    std::unique_ptr<crypto::RSAPrivateKey> signing_key(
-        PolicyBuilder::CreateTestSigningKey());
-    ASSERT_TRUE(policy_server_.SetSigningKeyAndSignature(
-        signing_key.get(), PolicyBuilder::GetTestSigningKeySignature()));
-    signing_key.reset();
-    policy_server_.RegisterClient(PolicyBuilder::kFakeToken,
-                                  PolicyBuilder::kFakeDeviceId,
-                                  {} /* state_keys */);
-    ASSERT_TRUE(policy_server_.Start());
-
-    DevicePolicyCrosBrowserTest::SetUp();
-  }
-
   virtual void SetupDevicePolicy() = 0;
 
   void SetUpInProcessBrowserTestFixture() override {
@@ -475,8 +460,6 @@ class PolicyProvidedTrustAnchorsDeviceLocalAccountTest
     command_line->AppendSwitch(chromeos::switches::kForceLoginManagerInTests);
     command_line->AppendSwitchASCII(chromeos::switches::kLoginProfile, "user");
     command_line->AppendSwitch(chromeos::switches::kOobeSkipPostLogin);
-    command_line->AppendSwitchASCII(switches::kDeviceManagementUrl,
-                                    policy_server_.GetServiceURL().spec());
   }
 
   void WaitForSessionStart() {
@@ -487,7 +470,7 @@ class PolicyProvidedTrustAnchorsDeviceLocalAccountTest
         .Wait();
   }
 
-  LocalPolicyTestServer policy_server_;
+  chromeos::LocalPolicyTestServerMixin local_policy_mixin_{&mixin_host_};
 
   const AccountId device_local_account_id_ =
       AccountId::FromUserEmail(GenerateDeviceLocalAccountUserId(
@@ -514,9 +497,7 @@ class PolicyProvidedTrustAnchorsPublicSessionTest
     account->set_type(
         em::DeviceLocalAccountInfoProto::ACCOUNT_TYPE_PUBLIC_SESSION);
     RefreshDevicePolicy();
-    ASSERT_TRUE(
-        policy_server_.UpdatePolicy(dm_protocol::kChromeDevicePolicyType,
-                                    std::string(), proto.SerializeAsString()));
+    ASSERT_TRUE(local_policy_mixin_.UpdateDevicePolicy(proto));
   }
 
   void StartLogin() {

chrome/test/BUILD.gn

@@ -1879,6 +1879,8 @@ test("browser_tests") {
         "../browser/chromeos/login/test/hid_controller_mixin.h",
         "../browser/chromeos/login/test/https_forwarder.cc",
         "../browser/chromeos/login/test/https_forwarder.h",
+        "../browser/chromeos/login/test/local_policy_test_server_mixin.cc",
+        "../browser/chromeos/login/test/local_policy_test_server_mixin.h",
         "../browser/chromeos/login/test/oobe_base_test.cc",
         "../browser/chromeos/login/test/oobe_base_test.h",
         "../browser/chromeos/login/ui/captive_portal_window_browsertest.cc",