Add support for reading .gypi files.

tools/gn/function_exec_script.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 "base/command_line.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/process/kill.h"
 #include "base/process/launch.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 392 matching lines @@
     if (!output.empty())
       msg += " and printed out:\n\n" + output;
     else
       msg += ".";
     *err = Err(function->function(), "Script returned non-zero exit code.",
                msg);
     return Value();
   }
 
   // Default to None value for the input conversion if unspecified.
-  return ConvertInputToValue(output, function,
+  return ConvertInputToValue(scope->settings(), output, function,
                              args.size() >= 3 ? args[2] : Value(), err);
 }
 
 }  // namespace functions