Add error handling to random access file

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 "bin/file.h"
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/globals.h"
@@ skipping 391 matching lines @@
 Dart_CObject* CObject::NewByteArray(int length) {
   Dart_CObject* cobject = New(Dart_CObject::kByteArray, length);
   cobject->value.as_byte_array.length = length;
   cobject->value.as_byte_array.values = reinterpret_cast<uint8_t*>(cobject + 1);
   return cobject;
 }
 
 
 static int kIllegalArgumentError = 1;
 static int kOSError = 2;
+static int kFileClosedError = 3;
 
 
 CObject* CObject::IllegalArgumentError() {
   CObjectArray* result = new CObjectArray(CObject::NewArray(1));
   result->SetAt(0, new CObjectInt32(CObject::NewInt32(kIllegalArgumentError)));
   return result;
 }
 
 
+CObject* CObject::FileClosedError() {
+  CObjectArray* result = new CObjectArray(CObject::NewArray(1));
+  result->SetAt(0, new CObjectInt32(CObject::NewInt32(kFileClosedError)));
+  return result;
+}
+
+
 CObject* CObject::NewOSError() {
   OSError os_error;
   return NewOSError(&os_error);
 }
 
 CObject* CObject::NewOSError(OSError* os_error) {
   CObject* error_message =
       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;
 }