GN: toolchain threading cleanup

tools/gn/toolchain.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/toolchain.h"
 
 #include "base/logging.h"
 #include "tools/gn/value.h"
 
 const char* Toolchain::kToolCc = "cc";
 const char* Toolchain::kToolCxx = "cxx";
 const char* Toolchain::kToolObjC = "objc";
 const char* Toolchain::kToolObjCxx = "objcxx";
 const char* Toolchain::kToolRc = "rc";
 const char* Toolchain::kToolAsm = "asm";
 const char* Toolchain::kToolAlink = "alink";
 const char* Toolchain::kToolSolink = "solink";
 const char* Toolchain::kToolLink = "link";
 const char* Toolchain::kToolStamp = "stamp";
 const char* Toolchain::kToolCopy = "copy";
 
 Toolchain::Tool::Tool() {
 }
 
 Toolchain::Tool::~Tool() {
 }
 
-Toolchain::Toolchain(const Label& label) : Item(label), is_default_(false) {
+Toolchain::Toolchain(const Settings* settings, const Label& label)
+    : Item(settings, label) {
 }
 
 Toolchain::~Toolchain() {
 }
 
 Toolchain* Toolchain::AsToolchain() {
   return this;
 }
 
 const Toolchain* Toolchain::AsToolchain() const {
@@ skipping 38 matching lines @@
 
 const Toolchain::Tool& Toolchain::GetTool(ToolType type) const {
   DCHECK(type != TYPE_NONE);
   return tools_[static_cast<size_t>(type)];
 }
 
 void Toolchain::SetTool(ToolType type, const Tool& t) {
   DCHECK(type != TYPE_NONE);
   tools_[static_cast<size_t>(type)] = t;
 }