GN: toolchain threading cleanup

tools/gn/config.h

 // Copyright (c) 2013 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 TOOLS_GN_CONFIG_H_
 #define TOOLS_GN_CONFIG_H_
 
 #include "base/compiler_specific.h"
 #include "tools/gn/config_values.h"
 #include "tools/gn/item.h"
 
 class Err;
 class ItemTree;
 class LocationRange;
 class Settings;
 
 // Represents a named config in the dependency graph.
 class Config : public Item {
  public:
-  Config(const Label& label);
+  Config(const Settings* settings, const Label& label);
   virtual ~Config();
 
   virtual Config* AsConfig() OVERRIDE;
   virtual const Config* AsConfig() const OVERRIDE;
 
   ConfigValues& config_values() { return config_values_; }
   const ConfigValues& config_values() const { return config_values_; }
 
   // Gets or creates a config.
   //
   // This is like the TargetManager is for Targets, but Configs are so much
   // simpler that this one function is all we need.
   static Config* GetConfig(const Settings* settings,
                            const LocationRange& specified_from_here,
                            const Label& label,
                            Item* dep_from,
                            Err* err);
 
  private:
   ConfigValues config_values_;
 
   DISALLOW_COPY_AND_ASSIGN(Config);
 };
 
 #endif  // TOOLS_GN_CONFIG_H_