Switch to standard integer types in tools/.

tools/gn/err.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/err.h"
 
+#include <stddef.h>
+
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/input_file.h"
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/standard_out.h"
 #include "tools/gn/tokenizer.h"
 #include "tools/gn/value.h"
 
 namespace {
@@ skipping 165 matching lines @@
   }
 
   // Optional help text.
   if (!help_text_.empty())
     OutputString(help_text_ + "\n");
 
   // Sub errors.
   for (const auto& sub_err : sub_errs_)
     sub_err.InternalPrintToStdout(true);
 }