Add yasm to the GN build

tools/gn/ninja_action_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_action_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 39 matching lines @@
   if (target_->output_type() == Target::ACTION_FOREACH) {
     // Write separate build lines for each input source file.
     WriteSourceRules(custom_rule_name, implicit_deps, args_template,
                      &output_files);
   } else {
     DCHECK(target_->output_type() == Target::ACTION);
 
     // Write a rule that invokes the script once with the outputs as outputs,
     // and the data as inputs.
     out_ << "build";
-    if (target_->action_values().has_depfile()) {
-      out_ << " ";
-      WriteDepfile(SourceFile());
-    }
     const Target::FileList& outputs = target_->action_values().outputs();
     for (size_t i = 0; i < outputs.size(); i++) {
       OutputFile output_path(
           RemovePrefix(outputs[i].value(),
                        settings_->build_settings()->build_dir().value()));
       output_files.push_back(output_path);
       out_ << " ";
       path_output_.WriteFile(out_, output_path);
     }
 
@@ skipping 130 matching lines @@
         helper_.GetTargetOutputFile(target_->datadeps()[i].ptr));
   }
 
   out_ << std::endl;
 }
 
 void NinjaActionTargetWriter::WriteOutputFilesForBuildLine(
     const FileTemplate& output_template,
     const SourceFile& source,
     std::vector<OutputFile>* output_files) {
-  // If there is a depfile specified we need to list it as the first output as
-  // that is what ninja will expect the depfile to refer to itself as.
-  if (target_->action_values().has_depfile()) {
-    out_ << " ";
-    WriteDepfile(source);
-  }
   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);
   }
 }
 
 void NinjaActionTargetWriter::WriteDepfile(const SourceFile& source) {
   std::vector<std::string> result;
   GetDepfileTemplate().ApplyString(source.value(), &result);
   path_output_.WriteFile(out_, OutputFile(result[0]));
 }
 
 FileTemplate NinjaActionTargetWriter::GetDepfileTemplate() const {
   std::vector<std::string> template_args;
   std::string depfile_relative_to_build_dir =
       RemovePrefix(target_->action_values().depfile().value(),
                    settings_->build_settings()->build_dir().value());
   template_args.push_back(depfile_relative_to_build_dir);
   return FileTemplate(template_args);
 }