base::ListValue::Append cleanup: pass unique_ptr instead of the released pointer.

extensions/browser/api/declarative/rules_registry.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 "extensions/browser/api/declarative/rules_registry.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 24 matching lines @@
 
 const char kSuccess[] = "";
 const char kDuplicateRuleId[] = "Duplicate rule ID: %s";
 const char kErrorCannotRemoveManifestRules[] =
     "Rules declared in the 'event_rules' manifest field cannot be removed";
 
 std::unique_ptr<base::Value> RulesToValue(
     const std::vector<linked_ptr<api::events::Rule>>& rules) {
   std::unique_ptr<base::ListValue> list(new base::ListValue());
   for (size_t i = 0; i < rules.size(); ++i)
-    list->Append(rules[i]->ToValue().release());
+    list->Append(rules[i]->ToValue());
   return std::move(list);

[Nico, 2016/06/09 16:57:35]

huh, why doesn't clang issue a -Wpessimizing-move here?

[dcheng, 2016/06/09 17:09:46]

C++11 still requires an explicit std::move() here, since it's converting from
unique_ptr<ListValue> to unique_ptr<Value>. With C++14, I think that will no
longer be the case (though I think it's still a move under the hood).

 }
 
 std::vector<linked_ptr<api::events::Rule>> RulesFromValue(
     const base::Value* value) {
   std::vector<linked_ptr<api::events::Rule>> rules;
 
   const base::ListValue* list = NULL;
   if (!value || !value->GetAsList(&list))
     return rules;
 
@@ skipping 370 matching lines @@
   for (i = identifiers.begin(); i != identifiers.end(); ++i)
     used_rule_identifiers_[extension_id].erase(*i);
 }
 
 void RulesRegistry::RemoveAllUsedRuleIdentifiers(
     const std::string& extension_id) {
   used_rule_identifiers_.erase(extension_id);
 }
 
 }  // namespace extensions