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..dc4540f66df0dbc88750553580775256612860de 100755
--- a/tools/isolate/run_test_from_archive.py
+++ b/tools/isolate/run_test_from_archive.py
@@ -117,7 +117,14 @@ 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)
+    remote_file = urllib.urlopen(file_or_url)

[Marc-Antoine Ruel (Google), 2012/04/23 23:50:14]

I'd prefer to keep using urlretrieve(). Albeit it's a bit clunky to do;
http://stackoverflow.com/questions/1308542/how-to-catch-404-error-in-urllib-u...

The main issue I have is about keeping the whole data in memory, some files may
be over 1gb in size so buffering it all and then writing it may not be the most
efficient thing.

+    if remote_file.getcode() != 200:
+      logging.error('Failed to download ' + file_or_url)
+      return
+
+    f = open(dest, 'wb')
+    f.write(remote_file.read())
+    f.close()
   else:
     shutil.copy(file_or_url, dest)