Add typed data interface to Dart API, this only changes the C++ API as dicussed in a previous email…

bin/io_buffer.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 "bin/io_buffer.h"
 
 Dart_Handle IOBuffer::Allocate(intptr_t size, uint8_t **buffer) {
   uint8_t* data = Allocate(size);
-  Dart_Handle result = Dart_NewExternalByteArray(data, size,
+  Dart_Handle result = Dart_NewExternalTypedData(kUint8,
+                                                 data, size,
                                                  data, IOBuffer::Finalizer);
   if (Dart_IsError(result)) {
     Free(data);
     Dart_PropagateError(result);
   }
   if (buffer != NULL) {
     *buffer = data;
   }
   return result;
 }
 
 uint8_t* IOBuffer::Allocate(intptr_t size) {
   return new uint8_t[size];
 }