PasswordStore: Clean up expectations about rewriting vectors of forms

chrome/browser/password_manager/password_store_mac.cc

 // Copyright (c) 2012 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 "chrome/browser/password_manager/password_store_mac.h"
 #include "chrome/browser/password_manager/password_store_mac_internal.h"
 
 #include <CoreServices/CoreServices.h>
 #include <set>
 #include <string>
@@ skipping 1086 matching lines @@
 void PasswordStoreMac::GetAutofillableLoginsImpl(
     scoped_ptr<PasswordStore::GetLoginsRequest> request) {
   DCHECK(request->result()->empty());
   FillAutofillableLogins(request->result());
   ForwardLoginsResult(request.Pass());
 }
 
 bool PasswordStoreMac::FillAutofillableLogins(
     ScopedVector<autofill::PasswordForm>* forms) {
   DCHECK(thread_->message_loop() == base::MessageLoop::current());
+  forms->clear();
 
   ScopedVector<PasswordForm> database_forms;
   if (!login_metadata_db_ ||
       !login_metadata_db_->GetAutofillableLogins(&database_forms))
     return false;
 
   internal_keychain_helpers::GetPasswordsForForms(*keychain_, &database_forms,
                                                   forms);
 
   if (!database_forms.empty()) {
@@ skipping 72 matching lines @@
   ScopedVector<PasswordForm> forms_with_keychain_entry;
   internal_keychain_helpers::GetPasswordsForForms(*keychain_, &database_forms,
                                                   &forms_with_keychain_entry);
 
   // Clean up any orphaned database entries.
   RemoveDatabaseForms(&database_forms);
 
   // Move the orphaned DB forms to the output parameter.
   AppendSecondToFirst(orphaned_forms, &database_forms);
 }