[Password Manager] Check the success of extracting FormData in PasswordForm creation

components/autofill/content/renderer/password_form_conversion_utils_browsertest.cc

 // Copyright 2013 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.
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_util.h"
@@ skipping 1452 matching lines @@
   builder.AddTextField("username", "johnsmith", nullptr);
   builder.AddPasswordField("password", "secret", nullptr);
   std::string html = builder.ProduceHTML();
 
   std::unique_ptr<PasswordForm> password_form =
       LoadHTMLAndConvertForm(html, nullptr, true);
   ASSERT_TRUE(password_form);
   EXPECT_FALSE(password_form->does_look_like_signup_form);
 }
 
+TEST_F(MAYBE_PasswordFormConversionUtilsTest, TooManyFieldsToParseForm) {
+  PasswordFormBuilder builder(kTestFormActionURL);
+  for (size_t i = 0; i < form_util::kMaxParseableFields + 1; ++i)
+    builder.AddTextField("id", "value", "autocomplete");
+  std::unique_ptr<PasswordForm> password_form =
+      LoadHTMLAndConvertForm(builder.ProduceHTML(), nullptr, false);
+  EXPECT_FALSE(password_form);
+}
+
 }  // namespace autofill