Fix a memory leak in PasswordStoreMac

chrome/browser/password_manager/password_store_mac_internal.h

 // 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.
 
 #ifndef CHROME_BROWSER_PASSWORD_MANAGER_PASSWORD_STORE_MAC_INTERNAL_H_
 #define CHROME_BROWSER_PASSWORD_MANAGER_PASSWORD_STORE_MAC_INTERNAL_H_
 
 #include <Security/Security.h>
 
 #include <string>
@@ skipping 12 matching lines @@
   // |keychain|, so the caller must make sure that the keychain outlives the
   // created object.
   explicit MacKeychainPasswordFormAdapter(const AppleKeychain* keychain);
 
   // Returns PasswordForms for each keychain entry that could be used to fill
   // |form|. Caller is responsible for deleting the returned forms.
   std::vector<autofill::PasswordForm*> PasswordsFillingForm(
       const std::string& signon_realm,
       autofill::PasswordForm::Scheme scheme);
 
-  // Returns the PasswordForm for the Keychain entry that matches |form| on all
-  // of the fields that uniquely identify a Keychain item, or NULL if there is
-  // no such entry.
-  // Caller is responsible for deleting the returned form.
-  autofill::PasswordForm* PasswordExactlyMatchingForm(
-      const autofill::PasswordForm& query_form);
+  // Returns true if there is the Keychain entry that matches |query_form| on
+  // all of the fields that uniquely identify a Keychain item.
+  bool HasPasswordExactlyMatchingForm(const autofill::PasswordForm& query_form);
 
   // Returns true if the keychain contains any items that are mergeable with
   // |query_form|. This is different from actually extracting the passwords
   // and checking the return count, since doing that would require reading the
   // passwords from the keychain, thus potentially triggering authorizaiton UI,
   // whereas this won't.
   bool HasPasswordsMergeableWithForm(
       const autofill::PasswordForm& query_form);
 
   // Returns all keychain items of types corresponding to password forms.
@@ skipping 164 matching lines @@
 // in |item_form_pairs| that could be merged with |query_form|.
 // Caller is responsible for deleting the returned forms.
 std::vector<autofill::PasswordForm*> ExtractPasswordsMergeableWithForm(
     const AppleKeychain& keychain,
     const std::vector<ItemFormPair>& item_form_pairs,
     const autofill::PasswordForm& query_form);
 
 }  // namespace internal_keychain_helpers
 
 #endif  // CHROME_BROWSER_PASSWORD_MANAGER_PASSWORD_STORE_MAC_INTERNAL_H_