Improve the encoding/decoding to/from system encoding on Windows

runtime/bin/main.cc

Index: runtime/bin/main.cc
diff --git a/runtime/bin/main.cc b/runtime/bin/main.cc
index bd5e8779e5c51d3f128b5ceee8775db8d59a5b60..cebd7e676ceb80d2f5c2a101db8992316311f70d 100644
--- a/runtime/bin/main.cc
+++ b/runtime/bin/main.cc
@@ -404,24 +404,6 @@ static bool ProcessMainOptions(const char* option,
 }
 
 
-// Convert all the arguments to UTF8. On Windows, the arguments are
-// encoded in the current code page and not UTF8.
-//
-// Returns true if the arguments are converted. In that case
-// each of the arguments need to be deallocated using free.
-static bool Utf8ConvertArgv(int argc, char** argv) {
-  int unicode_argc = 0;
-  wchar_t** unicode_argv = ShellUtils::GetUnicodeArgv(&unicode_argc);
-  if (unicode_argv == NULL) return false;
-  for (int i = 0; i < unicode_argc; i++) {
-    wchar_t* arg = unicode_argv[i];
-    argv[i] = StringUtils::WideToUtf8(arg);
-  }
-  ShellUtils::FreeUnicodeArgv(unicode_argv);
-  return true;
-}
-
-
 // Parse out the command line arguments. Returns -1 if the arguments
 // are incorrect, 0 otherwise.
 static int ParseArguments(int argc,
@@ -893,7 +875,7 @@ void main(int argc, char** argv) {
 
   // On Windows, the argv strings are code page encoded and not
   // utf8. We need to convert them to utf8.
-  bool argv_converted = Utf8ConvertArgv(argc, argv);
+  bool argv_converted = ShellUtils::GetUtf8Argv(argc, argv);
 
   // Parse command line arguments.
   if (ParseArguments(argc,