[iOS] Add unit tests for the add account sign-in mediator.

This CL is part of a series of refactors to move the existing sign-in
architecture to the Coordinator-Mediator design paradigm.

Fore more information, see go/chrome-ios-signin-migration.

Bug: 971989
Change-Id: I3131d6f20fa230b1c55cf9f979d3ed34aa38ccc4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2047249
Commit-Queue: Nohemi Fernandez <fernandex@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#742155}

ios/chrome/browser/ui/authentication/signin/add_account_signin/BUILD.gn

@@ -27,3 +27,24 @@ source_set("add_account_signin") {
   public_deps =
       [ "//ios/chrome/browser/ui/authentication/signin:signin_headers" ]
 }
+
+source_set("unit_tests") {
+  configs += [ "//build/config/compiler:enable_arc" ]
+  testonly = true
+  sources = [ "add_account_signin_mediator_unittest.mm" ]
+  deps = [
+    ":add_account_signin",
+    "//base/test:test_support",
+    "//components/prefs",
+    "//components/prefs:test_support",
+    "//ios/chrome/browser/browser_state:test_support",
+    "//ios/chrome/browser/signin",
+    "//ios/public/provider/chrome/browser/signin",
+    "//ios/public/provider/chrome/browser/signin:fake_chrome_identity",
+    "//ios/public/provider/chrome/browser/signin:test_support",
+    "//ios/web/public/test",
+    "//testing/gmock",
+    "//testing/gtest",
+    "//third_party/ocmock",
+  ]
+}

ios/chrome/browser/ui/authentication/signin/add_account_signin/add_account_signin_coordinator.mm

@@ -148,26 +148,13 @@ using signin_metrics::PromoAction;
 
 #pragma mark - AddAccountSigninMediatorDelegate
 
-- (void)handleUserConsentForIdentity:(ChromeIdentity*)identity {
-  // The UserSigninViewController is presented on top of the currently displayed
-  // view controller.
-  self.userSigninCoordinator = [SigninCoordinator
-      userSigninCoordinatorWithBaseViewController:self.baseViewController
-                                                      .presentedViewController
-                                          browser:self.browser
-                                         identity:identity
-                                      accessPoint:self.accessPoint
-                                      promoAction:self.promoAction];
-  [self.userSigninCoordinator start];
-}
-
-- (void)showAlertWithError:(NSError*)error identity:(ChromeIdentity*)identity {
+- (void)addAccountSigninMediatorFailedWith:(NSError*)error {
   DCHECK(error);
   __weak AddAccountSigninCoordinator* weakSelf = self;
   ProceduralBlock dismissAction = ^{
-    [weakSelf runCompletionCallbackWithSigninResult:
+    [weakSelf addAccountSigninMediatorFinishedWith:
                   SigninCoordinatorResultCanceledByUser
-                                           identity:identity];
+                                          identity:nil];
   };
 
   self.alertCoordinator =
@@ -175,9 +162,20 @@ using signin_metrics::PromoAction;
   [self.alertCoordinator start];
 }
 
-- (void)runCompletionCallbackWithSigninResult:
+- (void)addAccountSigninMediatorFinishedWith:
             (SigninCoordinatorResult)signinResult
                                     identity:(ChromeIdentity*)identity {
+  switch (self.signinIntent) {
+    case SigninIntentReauth: {
+      // Show the user consent screen to finish the sign-in operation.
+      [self handleUserConsentForIdentity:identity];
+      return;
+    }
+    case SigninIntentAddAccount: {
+      break;
+    }
+  }
+
   // Cleaning up and calling the |signinCompletion| should be done last.
   self.identityInteractionManager = nil;
   DCHECK(!self.alertCoordinator);
@@ -193,4 +191,19 @@ using signin_metrics::PromoAction;
   }
 }
 
+#pragma mark - Private
+
+- (void)handleUserConsentForIdentity:(ChromeIdentity*)identity {
+  // The UserSigninViewController is presented on top of the currently displayed
+  // view controller.
+  self.userSigninCoordinator = [SigninCoordinator
+      userSigninCoordinatorWithBaseViewController:self.baseViewController
+                                                      .presentedViewController
+                                          browser:self.browser
+                                         identity:identity
+                                      accessPoint:self.accessPoint
+                                      promoAction:self.promoAction];
+  [self.userSigninCoordinator start];
+}
+
 @end

ios/chrome/browser/ui/authentication/signin/add_account_signin/add_account_signin_mediator.h

@@ -20,19 +20,14 @@ class IdentityManager;
 // flows.
 @protocol AddAccountSigninMediatorDelegate
 
-// Handles the flow for obtaining user consent for the selected Chrome identity.
-// |identity| is the identity of the consenting account.
-- (void)handleUserConsentForIdentity:(ChromeIdentity*)identity;
-
-// Shows alert modal dialog.
+// Shows alert modal dialog and interrupts sign-in operation.
 // |error| is the error to be displayed.
-// |identity| is the identity of the added account.
-- (void)showAlertWithError:(NSError*)error identity:(ChromeIdentity*)identity;
+- (void)addAccountSigninMediatorFailedWith:(NSError*)error;
 
-// Runs the sign-in completion callback.
+// Completes the sign-in operation.
 // |signinResult| is the state of sign-in at add account flow completion.
 // |identity| is the identity of the added account.
-- (void)runCompletionCallbackWithSigninResult:
+- (void)addAccountSigninMediatorFinishedWith:
             (SigninCoordinatorResult)signinResult
                                     identity:(ChromeIdentity*)identity;
 

ios/chrome/browser/ui/authentication/signin/add_account_signin/add_account_signin_mediator.mm

@@ -70,31 +70,26 @@ using signin_metrics::PromoAction;
   }
 }
 
-#pragma mark - Utility methods
+#pragma mark - Private
 
 // Completes the add account flow including handling any errors that have not
-// been handled internally by ChromeIdentity. Will return YES if the sign-in
-// flow should be interrupted following this step. |identity| is the identity of
-// the added account. |error| is an error reported by the SSOAuth following
-// adding an account.
-- (BOOL)shouldInterruptSigninForIdentity:(ChromeIdentity*)identity
+// been handled internally by ChromeIdentity. Will return the sign-in status of
+// the user.
+// |identity| is the identity of the added account.
+// |error| is an error reported by the SSOAuth following adding an account.
+- (SigninCoordinatorResult)signinStateWithIdentity:(ChromeIdentity*)identity
                                              error:(NSError*)error {
-  if (!self.identityInteractionManager) {
-    return YES;
-  }
-
+  DCHECK(self.identityInteractionManager);
   if (error) {
+    DCHECK(!identity);
     // Filter out errors handled internally by ChromeIdentity.
-    if (!ShouldHandleSigninError(error)) {
-      [self.delegate runCompletionCallbackWithSigninResult:
-                         SigninCoordinatorResultCanceledByUser
-                                                  identity:identity];
-      return YES;
+    if (ShouldHandleSigninError(error)) {
+      return SigninCoordinatorResultInterrupted;
     }
-
-    [self.delegate showAlertWithError:error identity:identity];
+    return SigninCoordinatorResultCanceledByUser;
   }
-  return error;
+  DCHECK(identity);
+  return SigninCoordinatorResultSuccess;
 }
 
 // Handles the reauthentication operation for a user from the screen to enter
@@ -125,18 +120,29 @@ using signin_metrics::PromoAction;
                          email:base::SysUTF8ToNSString(email)
                     completion:^(ChromeIdentity* chromeIdentity,
                                  NSError* error) {
-                      __typeof(self) strongSelf = weakSelf;
-                      if (!strongSelf) {
-                        return;
+                      [weakSelf operationCompletedWithIdentity:chromeIdentity
+                                                         error:error];
+                    }];
+}
+
+// Handles the reauthentication or add account operation if the flow has not
+// been interrupted by a sign-in error.
+- (void)operationCompletedWithIdentity:(ChromeIdentity*)identity
+                                 error:(NSError*)error {
+  SigninCoordinatorResult signinResult = [self signinStateWithIdentity:identity
+                                                                 error:error];
+  switch (signinResult) {
+    case SigninCoordinatorResultSuccess:
+    case SigninCoordinatorResultCanceledByUser: {
+      [self.delegate addAccountSigninMediatorFinishedWith:signinResult
+                                                 identity:identity];
+      break;
+    }
+    case SigninCoordinatorResultInterrupted: {
+      [self.delegate addAccountSigninMediatorFailedWith:error];
+      break;
     }
-                      if ([strongSelf
-                              shouldInterruptSigninForIdentity:chromeIdentity
-                                                         error:error]) {
-                        return;
   }
-                      [strongSelf.delegate
-                          handleUserConsentForIdentity:chromeIdentity];
-                    }];
 }
 
 // Handles the add account operation for a user. Presents the screen to enter
@@ -146,17 +152,7 @@ using signin_metrics::PromoAction;
   __weak AddAccountSigninMediator* weakSelf = self;
   [self.identityInteractionManager
       addAccountWithCompletion:^(ChromeIdentity* identity, NSError* error) {
-        __typeof(self) strongSelf = weakSelf;
-        if (!strongSelf) {
-          return;
-        }
-        if ([strongSelf shouldInterruptSigninForIdentity:identity
-                                                   error:error]) {
-          return;
-        }
-        [strongSelf.delegate
-            runCompletionCallbackWithSigninResult:SigninCoordinatorResultSuccess
-                                         identity:identity];
+        [weakSelf operationCompletedWithIdentity:identity error:error];
       }];
 }
 

ios/chrome/browser/ui/authentication/signin/add_account_signin/add_account_signin_mediator_unittest.mm

+// Copyright 2020 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.
+
+#import "ios/chrome/browser/ui/authentication/signin/add_account_signin/add_account_signin_mediator.h"
+
+#import <UIKit/UIKit.h>
+
+#import "base/test/task_environment.h"
+#import "components/prefs/pref_registry_simple.h"
+#import "components/prefs/testing_pref_service.h"
+#import "components/signin/public/base/signin_pref_names.h"
+#import "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
+#import "ios/chrome/browser/signin/identity_manager_factory.h"
+#import "ios/public/provider/chrome/browser/signin/fake_chrome_identity.h"
+#import "ios/public/provider/chrome/browser/signin/fake_chrome_identity_interaction_manager.h"
+#import "ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.h"
+#import "testing/platform_test.h"
+#import "third_party/ocmock/OCMock/OCMock.h"
+#import "third_party/ocmock/gtest_support.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+// Constants for configuring a FakeChromeIdentity.
+const char kTestGaiaID[] = "fooID";
+const char kTestEmail[] = "foo@gmail.com";
+}  // namespace
+
+// Fake implementation of ChromeIdentityInteractionManagerDelegate that calls
+// completion callback.
+@interface FakeChromeIdentityInteractionManagerDelegate
+    : NSObject <ChromeIdentityInteractionManagerDelegate>
+@end
+
+@implementation FakeChromeIdentityInteractionManagerDelegate
+- (void)interactionManager:(ChromeIdentityInteractionManager*)interactionManager
+     presentViewController:(UIViewController*)viewController
+                  animated:(BOOL)animated
+                completion:(ProceduralBlock)completion {
+  if (completion) {
+    completion();
+  }
+}
+
+- (void)interactionManager:(ChromeIdentityInteractionManager*)interactionManager
+    dismissViewControllerAnimated:(BOOL)animated
+                       completion:(ProceduralBlock)completion {
+  if (completion) {
+    completion();
+  }
+}
+@end
+
+class AddAccountSigninMediatorTest : public PlatformTest {
+ public:
+  AddAccountSigninMediatorTest()
+      : browser_state_(TestChromeBrowserState::Builder().Build()),
+        identity_service_(
+            ios::FakeChromeIdentityService::GetInstanceFromChromeProvider()) {
+    manager_delegate_ =
+        [[FakeChromeIdentityInteractionManagerDelegate alloc] init];
+    identity_interaction_manager_ = GetIdentityInteractionManager();
+  }
+
+  FakeChromeIdentityInteractionManager* GetIdentityInteractionManager() {
+    FakeChromeIdentityInteractionManager* identity_interaction_manager =
+        ios::FakeChromeIdentityService::GetInstanceFromChromeProvider()
+            ->CreateFakeChromeIdentityInteractionManager(browser_state_.get(),
+                                                         manager_delegate_);
+    fake_identity_ = [FakeChromeIdentity
+        identityWithEmail:[NSString stringWithUTF8String:kTestEmail]
+                   gaiaID:[NSString stringWithUTF8String:kTestGaiaID]
+                     name:@"Foo"];
+    identity_interaction_manager.fakeIdentity = fake_identity_;
+    return identity_interaction_manager;
+  }
+
+  signin::IdentityManager* GetIdentityManager() {
+    return IdentityManagerFactory::GetForBrowserState(browser_state_.get());
+  }
+
+  // Registers account preferences that will be used in reauthentication.
+  PrefService* GetPrefService() {
+    TestingPrefServiceSimple* prefs = new TestingPrefServiceSimple();
+    PrefRegistrySimple* registry = prefs->registry();
+    registry->RegisterStringPref(prefs::kGoogleServicesLastUsername,
+                                 kTestEmail);
+    registry->RegisterStringPref(prefs::kGoogleServicesLastAccountId,
+                                 kTestGaiaID);
+    return prefs;
+  }
+
+ protected:
+  void SetUp() override {
+    mediator_ = [[AddAccountSigninMediator alloc]
+        initWithIdentityInteractionManager:identity_interaction_manager_
+                               prefService:GetPrefService()
+                           identityManager:GetIdentityManager()];
+    mediator_delegate_ =
+        OCMProtocolMock(@protocol(AddAccountSigninMediatorDelegate));
+    mediator_.delegate = mediator_delegate_;
+  }
+
+  void TearDown() override { EXPECT_OCMOCK_VERIFY(mediator_delegate_); }
+
+  // Needed for test browser state created by TestChromeBrowserState().
+  base::test::TaskEnvironment environment_;
+  std::unique_ptr<TestChromeBrowserState> browser_state_;
+
+  AddAccountSigninMediator* mediator_ = nil;
+  id mediator_delegate_ = nil;
+  id<ChromeIdentityInteractionManagerDelegate> manager_delegate_ = nil;
+
+  ios::FakeChromeIdentityService* identity_service_ = nil;
+  FakeChromeIdentityInteractionManager* identity_interaction_manager_ = nil;
+  FakeChromeIdentity* fake_identity_ = nil;
+};
+
+// Verifies the following state in the successful add account flow:
+//   - Account is added to the identity service
+//   - Completion callback is called with success state
+TEST_F(AddAccountSigninMediatorTest, AddAccountIntent) {
+  // Verify that completion was called with success state.
+  [[mediator_delegate_ expect]
+      addAccountSigninMediatorFinishedWith:SigninCoordinatorResultSuccess
+                                  identity:fake_identity_];
+
+  [mediator_
+      handleSigninIntent:SigninIntentAddAccount
+             accessPoint:signin_metrics::AccessPoint::ACCESS_POINT_SETTINGS
+             promoAction:signin_metrics::PromoAction::
+                             PROMO_ACTION_WITH_DEFAULT];
+  [identity_interaction_manager_ addAccountViewControllerDidTapSignIn];
+
+  // Account added.
+  EXPECT_TRUE(identity_service_->IsValidIdentity(fake_identity_));
+}
+
+// Verifies the following state in the add account flow with a user cancel:
+//   - Account is not added to the identity service
+//   - Completion callback is called with user cancel state
+TEST_F(AddAccountSigninMediatorTest, AddAccountIntentWithUserCancel) {
+  // Verify that completion was called with canceled result state.
+  [[mediator_delegate_ expect]
+      addAccountSigninMediatorFinishedWith:SigninCoordinatorResultCanceledByUser
+                                  identity:nil];
+  [[mediator_delegate_ reject] addAccountSigninMediatorFailedWith:[OCMArg any]];
+
+  [mediator_
+      handleSigninIntent:SigninIntentAddAccount
+             accessPoint:signin_metrics::AccessPoint::ACCESS_POINT_SETTINGS
+             promoAction:signin_metrics::PromoAction::
+                             PROMO_ACTION_WITH_DEFAULT];
+  [identity_interaction_manager_ addAccountViewControllerDidTapCancel];
+
+  // No account is present.
+  EXPECT_FALSE(identity_service_->HasIdentities());
+}
+
+// Verifies the following state in the add account flow with an error handled by
+// the mediator:
+//   - Account is not added to the identity service
+//   - Completion callback is called with user cancel state
+TEST_F(AddAccountSigninMediatorTest,
+       AddAccountIntentWithErrorHandledByMediator) {
+  // Verify that completion was called with canceled result state and an error
+  // is shown.
+  [[mediator_delegate_ expect] addAccountSigninMediatorFailedWith:[OCMArg any]];
+
+  [mediator_
+      handleSigninIntent:SigninIntentAddAccount
+             accessPoint:signin_metrics::AccessPoint::ACCESS_POINT_SETTINGS
+             promoAction:signin_metrics::PromoAction::
+                             PROMO_ACTION_WITH_DEFAULT];
+  [identity_interaction_manager_
+      addAccountViewControllerDidThrowUnhandledError];
+
+  // No account is present.
+  EXPECT_FALSE(identity_service_->HasIdentities());
+}
+
+// TODO(crbug.com/971989): Add the ReauthIntent test.
+// Verifies the following state in the successful reauth flow:
+//   - Account is added to the identity service
+//   - Completion callback is called with success state
+
+// Verifies the following state in the reauth flow with a user cancel:
+//   - Account is not added to the identity service
+//   - Completion callback is called with user cancel state
+TEST_F(AddAccountSigninMediatorTest, ReauthIntentWithUserCancel) {
+  // Verify that completion was called with canceled result state.
+  [[mediator_delegate_ expect]
+      addAccountSigninMediatorFinishedWith:SigninCoordinatorResultCanceledByUser
+                                  identity:nil];
+  [[mediator_delegate_ reject] addAccountSigninMediatorFailedWith:[OCMArg any]];
+
+  [mediator_
+      handleSigninIntent:SigninIntentReauth
+             accessPoint:signin_metrics::AccessPoint::ACCESS_POINT_SETTINGS
+             promoAction:signin_metrics::PromoAction::
+                             PROMO_ACTION_WITH_DEFAULT];
+  [identity_interaction_manager_ addAccountViewControllerDidTapCancel];
+
+  // No account is present.
+  EXPECT_FALSE(identity_service_->HasIdentities());
+}
+
+// Verifies the following state in the reauth flow with an error handled by the
+// mediator:
+//   - Account is not added to the identity service
+//   - Completion callback is called with user cancel state
+TEST_F(AddAccountSigninMediatorTest, ReauthIntentWithErrorHandledByMediator) {
+  // Verify that completion was called with canceled result state and an error
+  // is shown.
+  [[mediator_delegate_ expect] addAccountSigninMediatorFailedWith:[OCMArg any]];
+
+  [mediator_
+      handleSigninIntent:SigninIntentReauth
+             accessPoint:signin_metrics::AccessPoint::ACCESS_POINT_SETTINGS
+             promoAction:signin_metrics::PromoAction::
+                             PROMO_ACTION_WITH_DEFAULT];
+  [identity_interaction_manager_
+      addAccountViewControllerDidThrowUnhandledError];
+
+  // No account is present.
+  EXPECT_FALSE(identity_service_->HasIdentities());
+}

ios/chrome/test/BUILD.gn

@@ -224,6 +224,7 @@ test("ios_chrome_unittests") {
     "//ios/chrome/browser/ui/app_launcher:unit_tests",
     "//ios/chrome/browser/ui/authentication:unit_tests",
     "//ios/chrome/browser/ui/authentication/cells:unit_tests",
+    "//ios/chrome/browser/ui/authentication/signin/add_account_signin:unit_tests",
     "//ios/chrome/browser/ui/autofill/cells:unit_tests",
     "//ios/chrome/browser/ui/autofill/manual_fill:unit_tests",
     "//ios/chrome/browser/ui/badges:unit_tests",

ios/public/provider/chrome/browser/BUILD.gn

@@ -41,6 +41,7 @@ source_set("test_support") {
     "//ios/public/provider/chrome/browser/images:test_support",
     "//ios/public/provider/chrome/browser/mailto:test_support",
     "//ios/public/provider/chrome/browser/omaha:test_support",
+    "//ios/public/provider/chrome/browser/signin",
     "//ios/public/provider/chrome/browser/signin:test_support",
     "//ios/public/provider/chrome/browser/spotlight:test_support",
     "//ios/public/provider/chrome/browser/ui",

ios/public/provider/chrome/browser/signin/fake_chrome_identity_interaction_manager.h

@@ -14,6 +14,15 @@
 // Fake identity that will be returned by the add account method.
 @property(nonatomic, weak) ChromeIdentity* fakeIdentity;
 
+// Simulates a user tapping the sign-in button.
+- (void)addAccountViewControllerDidTapSignIn;
+
+// Simulates a user tapping the cancel button.
+- (void)addAccountViewControllerDidTapCancel;
+
+// Simulates the user encountering an error not handled by ChromeIdentity.
+- (void)addAccountViewControllerDidThrowUnhandledError;
+
 @end
 
 #endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_SIGNIN_FAKE_CHROME_IDENTITY_INTERACTION_MANAGER_H_

ios/public/provider/chrome/browser/signin/fake_chrome_identity_interaction_manager.mm

@@ -6,6 +6,7 @@
 
 #include "base/mac/scoped_block.h"
 #import "ios/public/provider/chrome/browser/chrome_browser_provider.h"
+#import "ios/public/provider/chrome/browser/signin/chrome_identity_interaction_manager.h"
 #import "ios/public/provider/chrome/browser/signin/fake_chrome_identity_interaction_manager_constants.h"
 #import "ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.h"
 #include "ios/public/provider/chrome/browser/signin/signin_error_provider.h"
@@ -27,10 +28,6 @@
   BOOL _isCanceling;
 }
 
-- (void)addAccountViewControllerDidTapSignIn:(FakeAddAccountViewController*)vc;
-
-- (void)addAccountViewControllerDidTapCancel:(FakeAddAccountViewController*)vc;
-
 @end
 
 @implementation FakeAddAccountViewController
@@ -89,11 +86,11 @@
 }
 
 - (void)didTapSignIn:(id)sender {
-  [_manager addAccountViewControllerDidTapSignIn:self];
+  [_manager addAccountViewControllerDidTapSignIn];
 }
 
 - (void)didTapCancel:(id)sender {
-  [_manager addAccountViewControllerDidTapCancel:self];
+  [_manager addAccountViewControllerDidTapCancel];
 }
 
 @end
@@ -129,17 +126,22 @@
   _isCanceling = NO;
 }
 
-- (void)addAccountViewControllerDidTapSignIn:(FakeAddAccountViewController*)vc {
+- (void)addAccountViewControllerDidTapSignIn {
   ios::FakeChromeIdentityService::GetInstanceFromChromeProvider()
       ->AddIdentity(_fakeIdentity);
   [self dismissAndRunCompletionCallbackWithError:nil animated:YES];
 }
 
-- (void)addAccountViewControllerDidTapCancel:(FakeAddAccountViewController*)vc {
+- (void)addAccountViewControllerDidTapCancel {
   [self dismissAndRunCompletionCallbackWithError:[self canceledError]
                                         animated:YES];
 }
 
+- (void)addAccountViewControllerDidThrowUnhandledError {
+  [self dismissAndRunCompletionCallbackWithError:[self unhandledError]
+                                        animated:YES];
+}
+
 #pragma mark Helper
 
 - (void)dismissAndRunCompletionCallbackWithError:(NSError*)error
@@ -174,4 +176,8 @@
                          userInfo:nil];
 }
 
+- (NSError*)unhandledError {
+  return [NSError errorWithDomain:@"" code:-1 userInfo:nil];
+}
+
 @end

ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.h

@@ -9,6 +9,7 @@
 
 #include "testing/gmock/include/gmock/gmock.h"
 
+@class FakeChromeIdentityInteractionManager;
 @class NSMutableArray;
 
 namespace ios {
@@ -31,6 +32,10 @@ class FakeChromeIdentityService : public ChromeIdentityService {
   ChromeIdentityInteractionManager* CreateChromeIdentityInteractionManager(
       ChromeBrowserState* browser_state,
       id<ChromeIdentityInteractionManagerDelegate> delegate) const override;
+  FakeChromeIdentityInteractionManager*
+  CreateFakeChromeIdentityInteractionManager(
+      ChromeBrowserState* browser_state,
+      id<ChromeIdentityInteractionManagerDelegate> delegate) const;
 
   bool IsValidIdentity(ChromeIdentity* identity) const override;
   ChromeIdentity* GetIdentityWithGaiaID(

ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.mm

@@ -129,7 +129,14 @@ ChromeIdentityInteractionManager*
 FakeChromeIdentityService::CreateChromeIdentityInteractionManager(
     ChromeBrowserState* browser_state,
     id<ChromeIdentityInteractionManagerDelegate> delegate) const {
-  ChromeIdentityInteractionManager* manager =
+  return CreateFakeChromeIdentityInteractionManager(browser_state, delegate);
+}
+
+FakeChromeIdentityInteractionManager*
+FakeChromeIdentityService::CreateFakeChromeIdentityInteractionManager(
+    ChromeBrowserState* browser_state,
+    id<ChromeIdentityInteractionManagerDelegate> delegate) const {
+  FakeChromeIdentityInteractionManager* manager =
       [[FakeChromeIdentityInteractionManager alloc] init];
   manager.delegate = delegate;
   return manager;

ios/public/provider/chrome/browser/test_chrome_browser_provider.h

@@ -22,6 +22,7 @@ class TestChromeBrowserProvider : public ChromeBrowserProvider {
 
   // ChromeBrowserProvider:
   SigninResourcesProvider* GetSigninResourcesProvider() override;
+  SigninErrorProvider* GetSigninErrorProvider() override;
   void SetChromeIdentityServiceForTesting(
       std::unique_ptr<ChromeIdentityService> service) override;
   ChromeIdentityService* GetChromeIdentityService() override;
@@ -40,6 +41,7 @@ class TestChromeBrowserProvider : public ChromeBrowserProvider {
   std::unique_ptr<BrandedImageProvider> branded_image_provider_;
   std::unique_ptr<ChromeIdentityService> chrome_identity_service_;
   std::unique_ptr<OmahaServiceProvider> omaha_service_provider_;
+  std::unique_ptr<SigninErrorProvider> signin_error_provider_;
   std::unique_ptr<SigninResourcesProvider> signin_resources_provider_;
   std::unique_ptr<VoiceSearchProvider> voice_search_provider_;
   std::unique_ptr<UserFeedbackProvider> user_feedback_provider_;

ios/public/provider/chrome/browser/test_chrome_browser_provider.mm

@@ -12,6 +12,7 @@
 #include "ios/public/provider/chrome/browser/mailto/test_mailto_handler_provider.h"
 #include "ios/public/provider/chrome/browser/omaha/test_omaha_service_provider.h"
 #include "ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.h"
+#include "ios/public/provider/chrome/browser/signin/signin_error_provider.h"
 #include "ios/public/provider/chrome/browser/signin/test_signin_resources_provider.h"
 #import "ios/public/provider/chrome/browser/spotlight/test_spotlight_provider.h"
 #import "ios/public/provider/chrome/browser/ui/fullscreen_provider.h"
@@ -30,6 +31,7 @@ TestChromeBrowserProvider::TestChromeBrowserProvider()
           std::make_unique<TestAppDistributionProvider>()),
       branded_image_provider_(std::make_unique<TestBrandedImageProvider>()),
       omaha_service_provider_(std::make_unique<TestOmahaServiceProvider>()),
+      signin_error_provider_(std::make_unique<SigninErrorProvider>()),
       signin_resources_provider_(
           std::make_unique<TestSigninResourcesProvider>()),
       voice_search_provider_(std::make_unique<TestVoiceSearchProvider>()),
@@ -57,6 +59,10 @@ void TestChromeBrowserProvider::SetChromeIdentityServiceForTesting(
   chrome_identity_service_.swap(service);
 }
 
+SigninErrorProvider* TestChromeBrowserProvider::GetSigninErrorProvider() {
+  return signin_error_provider_.get();
+}
+
 ChromeIdentityService* TestChromeBrowserProvider::GetChromeIdentityService() {
   if (!chrome_identity_service_) {
     chrome_identity_service_.reset(new FakeChromeIdentityService());