Adding mediator for Sign-in promo

ios/chrome/browser/ui/settings/cells/signin_promo_item_unittest.mm

-// Copyright 2017 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/settings/cells/signin_promo_item.h"
-
-#import <CoreGraphics/CoreGraphics.h>
-#import <UIKit/UIKit.h>
-
-#import "ios/third_party/material_components_ios/src/components/Buttons/src/MaterialButtons.h"
-#import "testing/gtest_mac.h"
-
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
-// Tests that the profile image, the profile name and the profile email are set
-// properly after a call to |configureCell:|.
-TEST(SigninPromoItemTest, ConfigureCell) {
-  SigninPromoItem* item = [[SigninPromoItem alloc] initWithType:0];
-  UIImage* image = [[UIImage alloc] init];
-
-  item.profileImage = image;
-  item.profileName = @"John Doe";
-  item.profileEmail = @"johndoe@gmail.com";
-
-  id cell = [[[item cellClass] alloc] init];
-  ASSERT_TRUE([cell isMemberOfClass:[SigninPromoCell class]]);
-
-  SigninPromoCell* signInCell = cell;
-  EXPECT_FALSE(signInCell.imageView.image);
-
-  [item configureCell:signInCell];
-
-  EXPECT_NSEQ(image, signInCell.imageView.image);
-  NSString* upperCaseProfileName = [item.profileName uppercaseString];
-  NSRange profileNameRange = [signInCell.signinButton.titleLabel.text
-      rangeOfString:upperCaseProfileName];
-  EXPECT_NE(profileNameRange.length, 0u);
-  NSRange profileEmailRange =
-      [signInCell.notMeButton.titleLabel.text rangeOfString:item.profileEmail];
-  EXPECT_NE(profileEmailRange.length, 0u);
-}