Fix GN unit tests

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"
@@ skipping 57 matching lines @@
   if (settings_->IsWin()) {
     // Send through gyp-win-tool and use a response file.
     std::string rspfile = custom_rule_name;
     if (has_sources())
       rspfile += ".$unique_name";
     rspfile += ".rsp";
 
     out_ << "rule " << custom_rule_name << std::endl;
     out_ << "  command = ";
     path_output_.WriteFile(out_, settings_->build_settings()->python_path());
-    out_ << " gyp-win-tool action-wrapper $arch " << rspfile << std::endl;
+    // TODO(brettw) this hardcodes "environment.x86" which is something that
+    // the Chrome Windows toolchain writes. We should have a way to invoke
+    // python without requiring this gyp_win_tool thing.
+    out_ << " gyp-win-tool action-wrapper environment.x86 " << rspfile
+         << std::endl;
     out_ << "  description = CUSTOM " << target_label << std::endl;
     out_ << "  restat = 1" << std::endl;
     out_ << "  rspfile = " << rspfile << std::endl;
 
     // The build command goes in the rsp file.
     out_ << "  rspfile_content = ";
     path_output_.WriteFile(out_, settings_->build_settings()->python_path());
     out_ << " ";
     path_output_.WriteFile(out_, target_->script_values().script());
     args_template.WriteWithNinjaExpansions(out_);
@@ skipping 75 matching lines @@
     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);
   }
 }