Update run_test_from_archive.py to handle 404

tools/isolate/run_test_from_archive.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Reads a manifest, creates a tree of hardlinks and runs the test.
 
 Keeps a local cache.
 """
 
@@ skipping 99 matching lines @@
 def open_remote(file_or_url):
   """Reads a file or url."""
   if re.match(r'^https?://.+$', file_or_url):
     return urllib.urlopen(file_or_url)
   return open(file_or_url, 'rb')
 
 
 def download_or_copy(file_or_url, dest):
   """Copies a file or download an url."""
   if re.match(r'^https?://.+$', file_or_url):
-    urllib.urlretrieve(file_or_url, dest)
+    try:
+      urllib.URLopener().retrieve(file_or_url, dest)

[csharp, 2012/04/24 15:18:47]

I don't see any need to create a new subclass since throwing an exception seems
fine to me.

+    except IOError:
+      logging.error('Failed to download ' + file_or_url)
   else:
     shutil.copy(file_or_url, dest)
 
 
 def get_free_space(path):
   """Returns the number of free bytes."""
   if sys.platform == 'win32':
     free_bytes = ctypes.c_ulonglong(0)
     ctypes.windll.kernel32.GetDiskFreeSpaceExW(
         ctypes.c_wchar_p(path), None, None, ctypes.pointer(free_bytes))
@@ skipping 172 matching lines @@
     parser.error('Unsupported args %s' % ' '.join(args))
 
   manifest = json.load(open_remote(options.manifest))
   return run_tha_test(
       manifest, os.path.abspath(options.cache), options.remote,
       options.max_cache_size, options.min_free_space)
 
 
 if __name__ == '__main__':
   sys.exit(main())