Enable Update Password UI on iOS behind a flag

ios/chrome/browser/passwords/ios_chrome_password_manager_client.h

 // 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.
 
 #ifndef IOS_CHROME_BROWSER_PASSWORDS_IOS_CHROME_PASSWORD_MANAGER_CLIENT_H_
 #define IOS_CHROME_BROWSER_PASSWORDS_IOS_CHROME_PASSWORD_MANAGER_CLIENT_H_
 
 #include "base/macros.h"
 #import "components/password_manager/core/browser/password_manager_client.h"
 #include "components/password_manager/sync/browser/sync_credentials_filter.h"
 #include "components/prefs/pref_member.h"
 
 namespace ios {
 class ChromeBrowserState;
 }
 
 namespace password_manager {
 class PasswordFormManager;
 }
 
 @protocol PasswordManagerClientDelegate
 
 // Shows UI to prompt the user to save the password.
 - (void)showSavePasswordInfoBar:
     (std::unique_ptr<password_manager::PasswordFormManager>)formToSave;
 
+// Shows UI to prompt the user to update the password.
+- (void)showUpdatePasswordInfoBar:
+    (std::unique_ptr<password_manager::PasswordFormManager>)formToUpdate;
+
 @property(readonly, nonatomic) ios::ChromeBrowserState* browserState;
 
 @property(readonly, nonatomic) const GURL& lastCommittedURL;
 
 @end
 
 // An iOS implementation of password_manager::PasswordManagerClient.
 class IOSChromePasswordManagerClient
     : public password_manager::PasswordManagerClient {
  public:
@@ skipping 38 matching lines @@
   // The preference associated with
   // password_manager::prefs::kPasswordManagerSavingEnabled.
   BooleanPrefMember saving_passwords_enabled_;
 
   const password_manager::SyncCredentialsFilter credentials_filter_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSChromePasswordManagerClient);
 };
 
 #endif  // IOS_CHROME_BROWSER_PASSWORDS_IOS_CHROME_PASSWORD_MANAGER_CLIENT_H_