Remove unused parameter.

tools/testing/dart/multitest.dart

 // Copyright (c) 2011, 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.
 
 #library("multitest");
 
 #import("dart:io");
 
 // Multitests are Dart test scripts containing lines of the form
 // " [some dart code] /// [key]: [error type]"
@@ skipping 99 matching lines @@
 
   // Copy all the tests into the output map tests, as multiline strings.
   for (String key in testsAsLines.getKeys()) {
     tests[key] =
         Strings.join(testsAsLines[key], line_separator) + line_separator;
   }
 }
 
 
 void DoMultitest(String filename,
-                 String component,
                  String outputDir,
                  String testDir,
                  Function doTest(String filename,
                                  bool isNegative,
                                  [bool isNegativeIfChecked,
                                   bool hasFatalTypeErrors,
                                   bool hasRuntimeErrors]),
                  Function multitestDone) {
   // Each new test is a single String value in the Map tests.
   Map<String, String> tests = new Map<String, String>();
@@ skipping 42 matching lines @@
   var split = testDir.split('/');
   var lastComponent = split.removeLast();
   Expect.isTrue(lastComponent == 'src');
   String path = '${generatedTestDir.path}/${split.last()}';
   Directory dir = new Directory(path);
   if (!dir.existsSync()) {
     dir.createSync();
   }
   return path;
 }