Enable Update Password UI on iOS behind a flag

ios/chrome/browser/passwords/ios_chrome_password_manager_client.mm

Index: ios/chrome/browser/passwords/ios_chrome_password_manager_client.mm
diff --git a/ios/chrome/browser/passwords/ios_chrome_password_manager_client.mm b/ios/chrome/browser/passwords/ios_chrome_password_manager_client.mm
index f24d098b23fa96cebb9cc813118274b4803b46b4..03913d8270c0ef7595029a1a83e4324d98e8cc5f 100644
--- a/ios/chrome/browser/passwords/ios_chrome_password_manager_client.mm
+++ b/ios/chrome/browser/passwords/ios_chrome_password_manager_client.mm
@@ -15,6 +15,7 @@
 #include "components/password_manager/core/common/password_manager_pref_names.h"
 #include "components/signin/core/browser/signin_manager_base.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/experimental_flags.h"
 #include "ios/chrome/browser/passwords/ios_chrome_password_store_factory.h"
 #include "ios/chrome/browser/signin/signin_manager_factory.h"
 #include "ios/chrome/browser/sync/ios_chrome_profile_sync_service_factory.h"
@@ -74,7 +75,13 @@ bool IOSChromePasswordManagerClient::PromptUserToSaveOrUpdatePassword(
     bool update_password) {
   if (form_to_save->IsBlacklisted())
     return false;
-  [delegate_ showSavePasswordInfoBar:std::move(form_to_save)];
+
+  if (update_password && IsUpdatePasswordUIEnabled()) {
+    [delegate_ showUpdatePasswordInfoBar:std::move(form_to_save)];
+  } else {
+    [delegate_ showSavePasswordInfoBar:std::move(form_to_save)];
+  }
+
   return true;
 }
 
@@ -120,6 +127,10 @@ bool IOSChromePasswordManagerClient::IsSavingAndFillingEnabledForCurrentPage()
          IsFillingEnabledForCurrentPage();
 }
 
+bool IOSChromePasswordManagerClient::IsUpdatePasswordUIEnabled() const {
+  return experimental_flags::IsUpdatePasswordUIEnabled();
+}
+
 const GURL& IOSChromePasswordManagerClient::GetLastCommittedEntryURL() const {
   return delegate_.lastCommittedURL;
 }