Remove Dartium for TIP of origin/master

tools/dartium/download_file.dart

-// Copyright (c) 2013, 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.
-
-import 'dart:async';
-import 'dart:io';
-
-Future downloadFile(Uri url, String destination) {
-  var client = new HttpClient();
-  return client
-      .getUrl(url)
-      .then((HttpClientRequest request) => request.close())
-      .then((HttpClientResponse response) {
-    if (response.statusCode != HttpStatus.OK) {
-      throw new Exception("Http status code (${response.statusCode}) "
-          "was not 200. Aborting.");
-    }
-    var sink = new File(destination).openWrite();
-    return response.pipe(sink).then((_) {
-      client.close();
-    });
-  });
-}
-
-void main(List<String> arguments) {
-  die(String message) {
-    print(message);
-    exit(1);
-  }
-
-  if (arguments.length != 2) {
-    var scriptName = Platform.script.pathSegments.last;
-    die("Usage dart $scriptName <url> <destination-file>");
-  }
-
-  var url = Uri.parse(arguments[0]);
-  var destination = arguments[1];
-
-  if (!['http', 'https'].contains(url.scheme)) {
-    die("Unsupported scheme in uri $url");
-  }
-
-  print("Downloading $url to $destination.");
-  downloadFile(url, destination).then((_) {
-    print("Download finished.");
-  }).catchError((error) {
-    die("An unexpected error occured: $error.");
-  });
-}