Fix a memory leak in PasswordStoreMac

chrome/browser/password_manager/password_store_mac.cc

Index: chrome/browser/password_manager/password_store_mac.cc
diff --git a/chrome/browser/password_manager/password_store_mac.cc b/chrome/browser/password_manager/password_store_mac.cc
index 5fad2ae20e1fbb20bbd5770af9e9a52b7d41ee8d..3abc45ff7c8b1377d3458ec4ac4fdbec5d755709 100644
--- a/chrome/browser/password_manager/password_store_mac.cc
+++ b/chrome/browser/password_manager/password_store_mac.cc
@@ -618,19 +618,19 @@ std::vector<PasswordForm*> MacKeychainPasswordFormAdapter::PasswordsFillingForm(
   return ConvertKeychainItemsToForms(&keychain_items);
 }
 
-PasswordForm* MacKeychainPasswordFormAdapter::PasswordExactlyMatchingForm(
-    const PasswordForm& query_form) {
+scoped_ptr<PasswordForm> MacKeychainPasswordFormAdapter::
+    PasswordExactlyMatchingForm(const PasswordForm& query_form) {
   SecKeychainItemRef keychain_item = KeychainItemForForm(query_form);
   if (keychain_item) {
-    PasswordForm* form = new PasswordForm();
+    scoped_ptr<PasswordForm> form(new PasswordForm);
     internal_keychain_helpers::FillPasswordFormFromKeychainItem(*keychain_,
                                                                 keychain_item,
-                                                                form,
+                                                                form.get(),
                                                                 true);
     keychain_->Free(keychain_item);
-    return form;
+    return form.Pass();
   }
-  return NULL;
+  return scoped_ptr<PasswordForm>();
 }
 
 bool MacKeychainPasswordFormAdapter::HasPasswordsMergeableWithForm(
@@ -942,9 +942,7 @@ PasswordStoreChangeList PasswordStoreMac::RemoveLoginImpl(
     // handle deletes on them the way we would for an imported item.)
     MacKeychainPasswordFormAdapter owned_keychain_adapter(keychain_.get());
     owned_keychain_adapter.SetFindsOnlyOwnedItems(true);
-    PasswordForm* owned_password_form =
-        owned_keychain_adapter.PasswordExactlyMatchingForm(form);
-    if (owned_password_form) {
+    if (owned_keychain_adapter.PasswordExactlyMatchingForm(form)) {

[Ilya Sherman, 2014/08/12 00:31:51]

Hmm, could the method be changed to instead just return a boolean value, rather
than returning a pointer to the form?

[vasilii, 2014/08/12 09:17:37]

The returned value is used in unit tests. With boolean it'll be more difficult
to test.

[Ilya Sherman, 2014/08/12 17:21:25]

Hmm, why do the tests need more information that the production code?  In
general, it's better to simplify production code and to test public APIs.

[vasilii, 2014/08/13 09:56:46]

Done.

       // If we don't have other forms using it (i.e., a form differing only by
       // the names of the form elements), delete the keychain entry.
       if (!DatabaseHasFormMatchingKeychainForm(form)) {