Add FileSystemWatcher class to dart:io.

runtime/bin/socket.cc

Index: runtime/bin/socket.cc
diff --git a/runtime/bin/socket.cc b/runtime/bin/socket.cc
index 13467afd737cc46c4368dbb7aa2e3ed2d5324670..a80bb7df08a3313d3fb9cc7a9dcde01b4e35659e 100644
--- a/runtime/bin/socket.cc
+++ b/runtime/bin/socket.cc
@@ -276,7 +276,7 @@ void FUNCTION_NAME(Socket_GetType)(Dart_NativeArguments args) {
 void FUNCTION_NAME(Socket_GetStdioHandle)(Dart_NativeArguments args) {
   Dart_Handle socket_obj = Dart_GetNativeArgument(args, 0);
   intptr_t num =
-      DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 1));
+      DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 1));
   ASSERT(num == 0 || num == 1 || num == 2);
   intptr_t socket = Socket::GetStdioHandle(num);
   Dart_Handle err = Socket::SetSocketIdNativeField(socket_obj, socket);
@@ -285,6 +285,15 @@ void FUNCTION_NAME(Socket_GetStdioHandle)(Dart_NativeArguments args) {
 }
 
 
+void FUNCTION_NAME(Socket_SetSocketId)(Dart_NativeArguments args) {
+  Dart_Handle socket_obj = Dart_GetNativeArgument(args, 0);
+  intptr_t id =
+      DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 1));
+  Dart_Handle err = Socket::SetSocketIdNativeField(socket_obj, id);
+  if (Dart_IsError(err)) Dart_PropagateError(err);
+}
+
+
 void FUNCTION_NAME(ServerSocket_CreateBindListen)(Dart_NativeArguments args) {
   Dart_Handle socket_obj = Dart_GetNativeArgument(args, 0);
   Dart_Handle host_obj = Dart_GetNativeArgument(args, 1);