[dart:io] Namespaces for file IO

runtime/bin/dartutils.h

Index: runtime/bin/dartutils.h
diff --git a/runtime/bin/dartutils.h b/runtime/bin/dartutils.h
index e8d06592a5aed4b6638d51b2c56096a8d3b88b67..2ba6e3b4b2710bd0c209b1225cb062b403111ea3 100644
--- a/runtime/bin/dartutils.h
+++ b/runtime/bin/dartutils.h
@@ -130,7 +130,8 @@ class DartUtils {
   static Dart_Handle SetupServiceLoadPort();
   static Dart_Handle SetupPackageRoot(const char* package_root,
                                       const char* packages_file);
-  static Dart_Handle SetupIOLibrary(const char* script_uri);
+  static Dart_Handle SetupIOLibrary(const char* namespc,
+                                    const char* script_uri);
 
   static bool PostNull(Dart_Port port_id);
   static bool PostInt32(Dart_Port port_id, int32_t value);