Enable Update Password UI on iOS behind a flag

ios/chrome/browser/passwords/ios_chrome_password_manager_client.h

Index: ios/chrome/browser/passwords/ios_chrome_password_manager_client.h
diff --git a/ios/chrome/browser/passwords/ios_chrome_password_manager_client.h b/ios/chrome/browser/passwords/ios_chrome_password_manager_client.h
index 2202ef1c7a8704d30bcaf91427d3ef7d052df885..f3b4a4e78695b7b7e5721f897970bccaf71484f2 100644
--- a/ios/chrome/browser/passwords/ios_chrome_password_manager_client.h
+++ b/ios/chrome/browser/passwords/ios_chrome_password_manager_client.h
@@ -24,6 +24,10 @@ class PasswordFormManager;
 - (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;
@@ -65,6 +69,7 @@ class IOSChromePasswordManagerClient
   void NotifyStorePasswordCalled() override;
   void ForceSavePassword() override;
   bool IsSavingAndFillingEnabledForCurrentPage() const override;
+  bool IsUpdatePasswordUIEnabled() const override;
   const GURL& GetLastCommittedEntryURL() const override;
   const password_manager::CredentialsFilter* GetStoreResultFilter()
       const override;