Make download_multivm script work on testers, not just builders.

tools/dartium/download_multivm.py

 #!/usr/bin/python
 
 # Copyright (c) 2014, 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.
 
 """Download archived multivm or dartium builds.
 
   Usage: download_multivm.py revision target_directory
 """
@@ skipping 18 matching lines @@
 
 def ExecuteCommand(cmd):
   print 'Executing: ' + ' '.join(cmd)
   subprocess.check_output(cmd)
 
 def main():
   revision = sys.argv[1]
   target_dir = sys.argv[2]
   archive_dir = (os.environ['BUILDBOT_BUILDERNAME']
                    .replace('linux', 'lucid64')
-                   .replace('multivm', 'multivm-dartium'))
+                   .replace('multivm', 'multivm-dartium')
+                   .replace('perf', 'build'))
   utils = imp.load_source('utils', os.path.join(TOOLS_DIR, 'utils.py'))
   with utils.TempDir() as temp_dir:
     archive_file = archive_dir + '-' + revision + '.zip'
     gs_source = '/'.join([GS_BUCKET, archive_dir, archive_file])
     zip_file = os.path.join(temp_dir, archive_file)
     ExecuteCommand([GSUTIL, 'cp', gs_source, zip_file])
 
     unzip_dir = zip_file.replace('.zip', '')
     if platform.system() == 'Windows':
       executable = os.path.join(SRC_DIR, 'third_party', 'lzma_sdk',
                                 'Executable', '7za.exe')
       ExecuteCommand([executable, 'x', '-aoa', '-o' + temp_dir, zip_file])
     else:
       ExecuteCommand(['unzip', zip_file, '-d', temp_dir])
 
     if os.path.exists(target_dir):
       shutil.rmtree(target_dir)
     shutil.move(unzip_dir, target_dir)
 
 if __name__ == '__main__':
   sys.exit(main())