GN: toolchain threading cleanup

tools/gn/ninja_script_target_writer.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/ninja_script_target_writer.h"
 
 #include "base/strings/string_util.h"
 #include "tools/gn/err.h"
 #include "tools/gn/file_template.h"
 #include "tools/gn/string_utils.h"
 #include "tools/gn/target.h"
 
 NinjaScriptTargetWriter::NinjaScriptTargetWriter(const Target* target,
+                                                 const Toolchain* toolchain,
                                                  std::ostream& out)
-    : NinjaTargetWriter(target, out),
+    : NinjaTargetWriter(target, toolchain, out),
       path_output_no_escaping_(
           target->settings()->build_settings()->build_dir(),
           ESCAPE_NONE, false) {
 }
 
 NinjaScriptTargetWriter::~NinjaScriptTargetWriter() {
 }
 
 void NinjaScriptTargetWriter::Run() {
   FileTemplate args_template(target_->script_values().args());
@@ skipping 119 matching lines @@
     if (args_template.has_substitutions())
       WriteArgsSubstitutions(sources[i], args_template);
   }
 }
 
 void NinjaScriptTargetWriter::WriteStamp(
     const std::vector<OutputFile>& output_files) {
   out_ << "build ";
   path_output_.WriteFile(out_, helper_.GetTargetOutputFile(target_));
   out_ << ": "
-       << helper_.GetRulePrefix(target_->settings()->toolchain())
+       << helper_.GetRulePrefix(target_->settings())
        << "stamp";
   for (size_t i = 0; i < output_files.size(); i++) {
     out_ << " ";
     path_output_.WriteFile(out_, output_files[i]);
   }
   out_ << std::endl;
 }
 
 void NinjaScriptTargetWriter::WriteOutputFilesForBuildLine(
     const FileTemplate& output_template,
     const SourceFile& source,
     std::vector<OutputFile>* output_files) {
   std::vector<std::string> output_template_result;
   output_template.ApplyString(source.value(), &output_template_result);
   for (size_t out_i = 0; out_i < output_template_result.size(); out_i++) {
     OutputFile output_path(output_template_result[out_i]);
     output_files->push_back(output_path);
     out_ << " ";
     path_output_.WriteFile(out_, output_path);
   }
 }