Revert 232657 "GN: toolchain threading cleanup"

trunk/src/tools/gn/config.cc

 // 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.
 
 #include "tools/gn/config.h"
 
 #include "tools/gn/err.h"
 #include "tools/gn/input_file_manager.h"
 #include "tools/gn/item_node.h"
 #include "tools/gn/item_tree.h"
 #include "tools/gn/scheduler.h"
 
-Config::Config(const Settings* settings, const Label& label)
-    : Item(settings, label) {
+Config::Config(const Label& label) : Item(label) {
 }
 
 Config::~Config() {
 }
 
 Config* Config::AsConfig() {
   return this;
 }
 
 const Config* Config::AsConfig() const {
   return this;
 }
 
 // static
 Config* Config::GetConfig(const Settings* settings,
                           const LocationRange& specified_from_here,
                           const Label& label,
                           Item* dep_from,
                           Err* err) {
   DCHECK(!label.is_null());
 
   ItemTree* tree = &settings->build_settings()->item_tree();
   base::AutoLock lock(tree->lock());
 
   ItemNode* node = tree->GetExistingNodeLocked(label);
   Config* config = NULL;
   if (!node) {
-    config = new Config(settings, label);
+    config = new Config(label);
     node = new ItemNode(config);
     node->set_originally_referenced_from_here(specified_from_here);
     tree->AddNodeLocked(node);
 
     // Only schedule loading the given target if somebody is depending on it
     // (and we optimize by not re-asking it to run the current file).
     // Otherwise, we're probably generating it right now.
     if (dep_from && dep_from->label().dir() != label.dir()) {
       settings->build_settings()->toolchain_manager().ScheduleInvocationLocked(
           specified_from_here, label.GetToolchainLabel(), label.dir(),
@@ skipping 20 matching lines @@
 
   // Keep a record of the guy asking us for this dependency. We know if
   // somebody is adding a dependency, that guy it himself not resolved.
   if (dep_from) {
     if (!dep_from->item_node()->AddDependency(
             settings->build_settings(), specified_from_here, node, err))
       return NULL;
   }
   return config;
 }