Chromad: Propagate DeviceLoginScreenDomainAutoComplete

This CL wires DeviceLoginScreenDomainAutoComplete policy with the Active
Directory login screen

BUG=chromium:841294
TEST=ActiveDirectoryLoginAutocompleteTest.TestAutocomplete

Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I29b264b251cc21b909a526bfb35c73110e6a93ea
Reviewed-on: https://chromium-review.googlesource.com/1069147Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Roman Sorokin <rsorokin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561000}

chrome/browser/chromeos/login/active_directory_login_browsertest.cc

@@ -49,6 +49,7 @@ constexpr char kAdOfflineAuthId[] = "offline-ad-auth";
 
 constexpr char kAdMachineName[] = "machine_name";
 constexpr char kTestActiveDirectoryUser[] = "test-user";
+constexpr char kTestUserRealm[] = "user.realm";
 constexpr char kAdMachineInput[] = "machineNameInput";
 constexpr char kAdMoreOptionsButton[] = "moreOptionsBtn";
 constexpr char kAdUserInput[] = "userInput";
@@ -99,7 +100,8 @@ class ActiveDirectoryLoginTest : public LoginManagerTest {
       : LoginManagerTest(true),
         // Using the same realm as supervised user domain. Should be treated as
         // normal realm.
-        test_realm_(user_manager::kSupervisedUserDomain) {}
+        test_realm_(user_manager::kSupervisedUserDomain),
+        autocomplete_realm_(test_realm_) {}
 
   ~ActiveDirectoryLoginTest() override = default;
 
@@ -214,7 +216,7 @@ class ActiveDirectoryLoginTest : public LoginManagerTest {
 
     // Checks if realm is set to autocomplete username.
     EXPECT_EQ(
-        "@" + test_realm_,
+        "@" + autocomplete_realm_,
         js_checker().GetString(
             JSElement(kAdOfflineAuthId, kAdAutocompleteRealm) + innerText));
 
@@ -338,6 +340,7 @@ class ActiveDirectoryLoginTest : public LoginManagerTest {
   }
 
   const std::string test_realm_;
+  std::string autocomplete_realm_;
 
  private:
   TestAuthPolicyClient* fake_auth_policy_client_;
@@ -345,6 +348,23 @@ class ActiveDirectoryLoginTest : public LoginManagerTest {
   DISALLOW_COPY_AND_ASSIGN(ActiveDirectoryLoginTest);
 };
 
+class ActiveDirectoryLoginAutocompleteTest : public ActiveDirectoryLoginTest {
+ public:
+  ActiveDirectoryLoginAutocompleteTest() = default;
+  void SetUpInProcessBrowserTestFixture() override {
+    enterprise_management::ChromeDeviceSettingsProto device_settings;
+    device_settings.mutable_login_screen_domain_auto_complete()
+        ->set_login_screen_domain_auto_complete(kTestUserRealm);
+    fake_auth_policy_client()->set_device_policy(device_settings);
+    autocomplete_realm_ = kTestUserRealm;
+
+    ActiveDirectoryLoginTest::SetUpInProcessBrowserTestFixture();
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ActiveDirectoryLoginAutocompleteTest);
+};
+
 }  // namespace
 
 // Marks as Active Directory enterprise device and OOBE as completed.
@@ -493,4 +513,17 @@ IN_PROC_BROWSER_TEST_F(ActiveDirectoryLoginTest,
   TriggerPasswordChangeScreen();
 }
 
+// Marks as Active Directory enterprise device and OOBE as completed.
+IN_PROC_BROWSER_TEST_F(ActiveDirectoryLoginAutocompleteTest,
+                       PRE_TestAutocomplete) {
+  MarkAsActiveDirectoryEnterprise();
+}
+
+// Tests that DeviceLoginScreenDomainAutoComplete policy overrides device realm
+// for user autocomplete.
+IN_PROC_BROWSER_TEST_F(ActiveDirectoryLoginAutocompleteTest, TestAutocomplete) {
+  TestLoginVisible();
+  TestDomainVisible();
+}
+
 }  // namespace chromeos

chrome/browser/resources/chromeos/login/screen_gaia_signin.js

@@ -1235,10 +1235,14 @@ login.createScreen('GaiaSigninScreen', 'gaia-signin', function() {
       this.loading = true;
       this.startLoadingTimer_();
       var ADAuthUI = this.getSigninFrame_();
-      if ('realm' in params) {
+      if ('realm' in params)
         ADAuthUI.realm = params['realm'];
+
+      if ('emailDomain' in params)
+        ADAuthUI.userRealm = '@' + params['emailDomain'];
+      else if ('realm' in params)
         ADAuthUI.userRealm = '@' + params['realm'];
-      }
+
       ADAuthUI.setUser(params['email']);
       this.onAuthReady_();
     },