Add EGTests for passwords settings on iOS

ios/chrome/browser/ui/settings/password_details_collection_view_controller.mm

 // 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.
 
 #import "ios/chrome/browser/ui/settings/password_details_collection_view_controller.h"
 
 #include "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/autofill/core/common/password_form.h"
 #include "components/password_manager/core/browser/affiliation_utils.h"
@@ skipping 275 matching lines @@
       }
     };
     [_weakReauthenticationModule
         attemptReauthWithLocalizedReason:
             l10n_util::GetNSString(IDS_IOS_SETTINGS_PASSWORD_REAUTH_REASON_COPY)
                                  handler:copyPasswordHandler];
   }
 }
 
 - (void)showCopyPasswordResultToast:(NSString*)message {
+  // TODO(crbug.com/159166): Route this through some delegate API to be able
+  // to mock it in the unittest, and avoid having an EGTest just for that?
   MDCSnackbarMessage* copyPasswordResultMessage =
       [MDCSnackbarMessage messageWithText:message];
   [MDCSnackbarManager showMessage:copyPasswordResultMessage];
 }
 
 - (void)deletePassword {
   [_weakDelegate deletePassword:_passwordForm];
 }
 
 #pragma mark - UICollectionViewDelegate
@@ skipping 32 matching lines @@
     case ItemTypeUsername:
     case ItemTypePassword:
       return [MDCCollectionViewCell
           cr_preferredHeightForWidth:CGRectGetWidth(collectionView.bounds)
                              forItem:item];
     default:
       return MDCCellDefaultOneLineHeight;
   }
 }
 
+#pragma mark - ForTesting
+
+- (void)setReauthenticationModule:
+    (id<ReauthenticationProtocol>)reauthenticationModule {
+  _weakReauthenticationModule = reauthenticationModule;
+}
+
 @end