[Password Manager] Remove "Nope" button from update passwords UI on iOS

ios/chrome/browser/passwords/ios_chrome_update_password_infobar_delegate.mm

Index: ios/chrome/browser/passwords/ios_chrome_update_password_infobar_delegate.mm
diff --git a/ios/chrome/browser/passwords/ios_chrome_update_password_infobar_delegate.mm b/ios/chrome/browser/passwords/ios_chrome_update_password_infobar_delegate.mm
index 7bd25cc82658cdb122d66a7178b18ee21631b50f..9a9a9ef9d34ef61b2eb8ea1d25ad6f47b26a7454 100644
--- a/ios/chrome/browser/passwords/ios_chrome_update_password_infobar_delegate.mm
+++ b/ios/chrome/browser/passwords/ios_chrome_update_password_infobar_delegate.mm
@@ -84,11 +84,14 @@ base::string16 IOSChromeUpdatePasswordInfoBarDelegate::GetMessageText() const {
                    IDS_IOS_PASSWORD_MANAGER_UPDATE_PASSWORD, GetBranding());
 }
 
+int IOSChromeUpdatePasswordInfoBarDelegate::GetButtons() const {
+  return BUTTON_OK;
+}
+
 base::string16 IOSChromeUpdatePasswordInfoBarDelegate::GetButtonLabel(
     InfoBarButton button) const {
-  return l10n_util::GetStringUTF16(
-      (button == BUTTON_OK) ? IDS_IOS_PASSWORD_MANAGER_UPDATE_BUTTON
-                            : IDS_IOS_PASSWORD_MANAGER_CANCEL_BUTTON);
+  DCHECK_EQ(BUTTON_OK, button);
+  return l10n_util::GetStringUTF16(IDS_IOS_PASSWORD_MANAGER_UPDATE_BUTTON);
 }
 
 bool IOSChromeUpdatePasswordInfoBarDelegate::Accept() {
@@ -101,7 +104,3 @@ bool IOSChromeUpdatePasswordInfoBarDelegate::Accept() {
   }
   return true;
 }
-
-bool IOSChromeUpdatePasswordInfoBarDelegate::Cancel() {
-  return true;
-}