Fix windows build

runtime/bin/dartutils.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/dartutils.h"
 
 #include "include/dart_api.h"
 
 #include "platform/assert.h"
 #include "platform/globals.h"
@@ skipping 251 matching lines @@
 }
 
 
 static uint8_t* SocketReadUntilEOF(intptr_t socket, intptr_t* response_len) {
   const intptr_t kInitialBufferSize = 16 * KB;
   intptr_t buffer_size = kInitialBufferSize;
   uint8_t* buffer = reinterpret_cast<uint8_t*>(malloc(buffer_size));
   ASSERT(buffer != NULL);
   intptr_t buffer_cursor = 0;
   do {
-    ssize_t bytes_read = Socket::Read(socket, &buffer[buffer_cursor],
+    int bytes_read = Socket::Read(socket, &buffer[buffer_cursor],
                                       buffer_size - buffer_cursor - 1);
     if (bytes_read < 0) {
       free(buffer);
       return NULL;
     }
 
     buffer_cursor += bytes_read;
 
     if (bytes_read == 0) {
       *response_len = buffer_cursor;
@@ skipping 820 matching lines @@
       new CObjectString(CObject::NewString(os_error->message()));
   CObjectArray* result = new CObjectArray(CObject::NewArray(3));
   result->SetAt(0, new CObjectInt32(CObject::NewInt32(kOSError)));
   result->SetAt(1, new CObjectInt32(CObject::NewInt32(os_error->code())));
   result->SetAt(2, error_message);
   return result;
 }
 
 }  // namespace bin
 }  // namespace dart