Remove ListValue::Append(raw ptr) on Mac and iOS

ios/chrome/browser/passwords/password_controller.mm

Index: ios/chrome/browser/passwords/password_controller.mm
diff --git a/ios/chrome/browser/passwords/password_controller.mm b/ios/chrome/browser/passwords/password_controller.mm
index d79a421bdae18414272175393c1255ec3cd00ccd..c6ece1808b7592845330e7a4b55555ed359abace 100644
--- a/ios/chrome/browser/passwords/password_controller.mm
+++ b/ios/chrome/browser/passwords/password_controller.mm
@@ -220,14 +220,14 @@ NSString* SerializePasswordFormFillData(
   auto usernameField = base::MakeUnique<base::DictionaryValue>();
   usernameField->SetString("name", formData.username_field.name);
   usernameField->SetString("value", formData.username_field.value);
-  fieldList->Append(usernameField.release());
+  fieldList->Append(std::move(usernameField));
 
   auto passwordField = base::MakeUnique<base::DictionaryValue>();
   passwordField->SetString("name", formData.password_field.name);
   passwordField->SetString("value", formData.password_field.value);
-  fieldList->Append(passwordField.release());
+  fieldList->Append(std::move(passwordField));
 
-  rootDict.Set("fields", fieldList.release());
+  rootDict.Set("fields", std::move(fieldList));
 
   std::string jsonString;
   base::JSONWriter::Write(rootDict, &jsonString);