Add FileSystemWatcher class to dart:io.

runtime/bin/socket_macos.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include <errno.h>  // NOLINT
 #include <stdio.h>  // NOLINT
 #include <stdlib.h>  // NOLINT
@@ skipping 174 matching lines @@
   struct stat buf;
   int result = fstat(fd, &buf);
   if (result == -1) return -1;
   if (S_ISCHR(buf.st_mode)) return File::kTerminal;
   if (S_ISFIFO(buf.st_mode)) return File::kPipe;
   if (S_ISREG(buf.st_mode)) return File::kFile;
   return File::kOther;
 }
 
 
-intptr_t Socket::GetStdioHandle(int num) {
-  return static_cast<intptr_t>(num);
+intptr_t Socket::GetStdioHandle(intptr_t num) {
+  return num;
 }
 
 
 AddressList<SocketAddress>* Socket::LookupAddress(const char* host,
                                                   int type,
                                                   OSError** os_error) {
   // Perform a name lookup for a host name.
   struct addrinfo hints;
   memset(&hints, 0, sizeof(hints));
   hints.ai_family = SocketAddress::FromType(type);
@@ skipping 200 matching lines @@
                                        IPPROTO_TCP,
                                        TCP_NODELAY,
                                        reinterpret_cast<char *>(&on),
                                        sizeof(on))) == 0;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)