[Password Manager] Modified to support saving passwords on forms without username fields.

components/password_manager/core/browser/password_form_manager.cc

Index: components/password_manager/core/browser/password_form_manager.cc
diff --git a/components/password_manager/core/browser/password_form_manager.cc b/components/password_manager/core/browser/password_form_manager.cc
index 7bda8bb035f0d7f6b93b9af74386d58b9b2d4b2d..59eff7cc5235d839e224c9b1fa90916d4553389f 100644
--- a/components/password_manager/core/browser/password_form_manager.cc
+++ b/components/password_manager/core/browser/password_form_manager.cc
@@ -227,9 +227,8 @@ bool PasswordFormManager::HasValidPasswordForm() {
   // do not contain username_element and password_element values.
   if (observed_form_.scheme != PasswordForm::SCHEME_HTML)
     return true;
-  return !observed_form_.username_element.empty() &&
-         (!observed_form_.password_element.empty() ||
-          !observed_form_.new_password_element.empty());
+  return !observed_form_.password_element.empty() ||
+         !observed_form_.new_password_element.empty();
 }
 
 void PasswordFormManager::ProvisionallySave(