Validate GN substitutions in args and rsp files.

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 <stddef.h>
 
 #include "base/strings/string_util.h"
 #include "tools/gn/deps_iterator.h"
@@ skipping 162 matching lines @@
       path_output_.WriteFile(out_, input_dep);
     }
     out_ << std::endl;
 
     // Response files require a unique name be defined.
     if (target_->action_values().uses_rsp_file())
       out_ << "  unique_name = " << i << std::endl;
 
     // The required types is the union of the args and response file. This
     // might theoretically duplicate a definition if the same substitution is
-    // used in both the args and the reponse file. However, this should be
+    // used in both the args and the response file. However, this should be
     // very unusual (normally the substitutions will go in one place or the
     // other) and the redundant assignment won't bother Ninja.
     SubstitutionWriter::WriteNinjaVariablesForSource(
         target_, settings_, sources[i],
         target_->action_values().args().required_types(),
         args_escape_options, out_);
     SubstitutionWriter::WriteNinjaVariablesForSource(
         target_, settings_, sources[i],
         target_->action_values().rsp_file_contents().required_types(),
         args_escape_options, out_);
@@ skipping 19 matching lines @@
     out_ << " ";
     path_output_.WriteFile(out_, (*output_files)[i]);
   }
 }
 
 void NinjaActionTargetWriter::WriteDepfile(const SourceFile& source) {
   path_output_.WriteFile(out_,
       SubstitutionWriter::ApplyPatternToSourceAsOutputFile(
           target_, settings_, target_->action_values().depfile(), source));
 }