Accept empty username as sync username in IsSyncAccountCredential

components/password_manager/sync/browser/password_sync_util_unittest.cc

 // Copyright 2015 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 "components/password_manager/sync/browser/password_sync_util.h"
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "components/autofill/core/common/password_form.h"
@@ skipping 48 matching lines @@
   const struct {
     PasswordForm form;
     std::string fake_sync_username;
     bool expected_result;
   } kTestCases[] = {
       {SimpleGaiaForm("sync_user@example.org"), "sync_user@example.org", true},
       {SimpleGaiaForm("non_sync_user@example.org"), "sync_user@example.org",
        false},
       {SimpleNonGaiaForm("sync_user@example.org"), "sync_user@example.org",
        false},
+      {SimpleGaiaForm(""), "sync_user@example.org", true},
+      {SimpleNonGaiaForm(""), "sync_user@example.org", false},
   };
 
   for (size_t i = 0; i < arraysize(kTestCases); ++i) {
     SCOPED_TRACE(testing::Message() << "i=" << i);
     SetSyncingPasswords(true);
     FakeSigninAs(kTestCases[i].fake_sync_username);
     EXPECT_EQ(kTestCases[i].expected_result,
               IsSyncAccountCredential(kTestCases[i].form, sync_service(),
                                       signin_manager()));
   }
 }
 
 }  // namespace sync_util
 }  // namespace password_manager