Use patching for dart:io.

runtime/bin/builtin_nolib.cc

 // Copyright (c) 2012, 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 <stdio.h>
 
 #include "include/dart_api.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 
 
 Builtin::builtin_lib_props Builtin::builtin_libraries_[] = {
-  /*      url_                 source_          has_natives_  */
-  { DartUtils::kBuiltinLibURL, NULL,            true  },
-  { DartUtils::kJsonLibURL,    NULL,            false },
-  { DartUtils::kUriLibURL,     NULL,            false },
-  { DartUtils::kCryptoLibURL,  NULL,            false },
-  { DartUtils::kIOLibURL,      NULL,            true  },
-  { DartUtils::kUtfLibURL,     NULL,            false }
+  /* { url_, source_, patch_url_, patch_source_, has_natives_ } */
+  { DartUtils::kBuiltinLibURL, NULL, NULL, NULL, true },
+  { DartUtils::kJsonLibURL, NULL, NULL, NULL, false },
+  { DartUtils::kUriLibURL, NULL, NULL, NULL, false },
+  { DartUtils::kCryptoLibURL, NULL, NULL, NULL, false },
+  { DartUtils::kIOLibURL, NULL, NULL, NULL, true  },
+  { DartUtils::kUtfLibURL, NULL, NULL, NULL, false }
 };
 
 
 Dart_Handle Builtin::Source(BuiltinLibraryId id) {
   ASSERT((sizeof(builtin_libraries_) / sizeof(builtin_lib_props)) ==
          kInvalidLibrary);
   return Dart_NewApiError("Unreachable code in Builtin::Source (%d).", id);
 }
 
 
@@ skipping 21 matching lines @@
     ASSERT(id > kUtfLibrary);
     library = Dart_LoadLibrary(url, Source(id));
     if (!Dart_IsError(library) && (builtin_libraries_[id].has_natives_)) {
       // Setup the native resolver for built in library functions.
       DART_CHECK_VALID(Dart_SetNativeResolver(library, NativeLookup));
     }
   }
   DART_CHECK_VALID(library);
   return library;
 }