Update run_test_from_archive.py to handle 404

tools/isolate/run_test_from_archive.py

Index: tools/isolate/run_test_from_archive.py
diff --git a/tools/isolate/run_test_from_archive.py b/tools/isolate/run_test_from_archive.py
index 2c56bc823384322c5dc06c5b6c0f046b81f2ff00..2223908f2500a43f6b52baf654af25dfe4cefa5d 100755
--- a/tools/isolate/run_test_from_archive.py
+++ b/tools/isolate/run_test_from_archive.py
@@ -117,7 +117,10 @@ def open_remote(file_or_url):
 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)