Rewrite base::JSONReader to be 35-40% faster, depending on the input string.

chrome/common/extensions/api/extension_api.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/common/extensions/api/extension_api.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 51 matching lines @@
 
 base::StringPiece ReadFromResource(int resource_id) {
   return ResourceBundle::GetSharedInstance().GetRawDataResource(resource_id);
 }
 
 scoped_ptr<ListValue> LoadSchemaList(const base::StringPiece& schema) {
   std::string error_message;
   scoped_ptr<Value> result(
       base::JSONReader::ReadAndReturnError(
           schema.as_string(),
-          base::JSON_PARSE_RFC,  // options
+          base::JSON_PARSE_RFC | base::JSON_DETACHABLE_CHILDREN,  // options
           NULL,  // error code
           &error_message));
   CHECK(result.get()) << error_message;
   CHECK(result->IsType(Value::TYPE_LIST));
   return scoped_ptr<ListValue>(static_cast<ListValue*>(result.release()));
 }
 
 DictionaryValue* FindListItem(const ListValue* list,
                               const std::string& property_name,
                               const std::string& property_value) {
@@ skipping 631 matching lines @@
   }
 }
 
 void ExtensionAPI::LoadAllSchemas() {
   while (unloaded_schemas_.size()) {
     LoadSchema(unloaded_schemas_.begin()->second);
   }
 }
 
 }  // namespace extensions