GN: toolchain threading cleanup

tools/gn/setup.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/setup.h"
 
 #include <stdlib.h>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ skipping 184 matching lines @@
   if (cmdline->HasSwitch(kTracelogSwitch))
     SaveTraces(cmdline->GetSwitchValuePath(kTracelogSwitch));
 
   return true;
 }
 
 // Setup -----------------------------------------------------------------------
 
 Setup::Setup()
     : CommonSetup(),
-      empty_toolchain_(Label()),
-      empty_settings_(&empty_build_settings_, &empty_toolchain_, std::string()),
+      empty_settings_(&empty_build_settings_, std::string()),
       dotfile_scope_(&empty_settings_) {
+  empty_settings_.set_toolchain_label(Label());
 }
 
 Setup::~Setup() {
 }
 
 bool Setup::DoSetup() {
   CommandLine* cmdline = CommandLine::ForCurrentProcess();
 
   scheduler_.set_verbose_logging(cmdline->HasSwitch(kSwitchVerbose));
   if (cmdline->HasSwitch(kTimeSwitch) ||
@@ skipping 211 matching lines @@
 }
 
 void DependentSetup::RunPreMessageLoop() {
   CommonSetup::RunPreMessageLoop();
 }
 
 bool DependentSetup::RunPostMessageLoop() {
   return CommonSetup::RunPostMessageLoop();
 }