Type conversion fixes, tools/ edition.

tools/gn/generate_test_gn_data.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 <fstream>
 #include <iostream>
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 20 matching lines @@
 base::FilePath RepoPathToPathName(const std::vector<int>& repo_path) {
   base::FilePath ret;
   for (size_t i = 0; i < repo_path.size(); i++) {
     ret = ret.Append(UTF8ToFilePath(base::IntToString(repo_path[i])));
   }
   return ret;
 }
 
 std::string TargetIndexToLetter(int target_index) {
   char ret[2];
-  ret[0] = 'a' + target_index;
+  ret[0] = static_cast<char>('a' + target_index);
   ret[1] = 0;
   return ret;
 }
 
 std::string RepoPathToTargetName(const std::vector<int>& repo_path,
                                  int target_index) {
   std::string ret;
   for (size_t i = 0; i < repo_path.size(); i++) {
     if (i != 0)
       ret.push_back('_');
@@ skipping 64 matching lines @@
   }
 }
 
 int main() {
   WriteLevel(std::vector<int>(), 5, 4, 3, 50);  // 781 files, 2343 targets
   //WriteLevel(std::vector<int>(), 6, 4, 2, 50);
   std::cout << "Wrote " << files_written << " files and "
             << targets_written << " targets.\n";
   return 0;
 }