Add functionality to download files from GCS, and include them in the Chromoting isolate.

testing/chromoting/download_test_files.py

+# Copyright (c) 2015 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.
+
+"""A script to download files required for Remoting integration tests from GCS.
+
+  The script expects 2 parameters:
+
+    input_files: a file containing the full path in GCS to each file that is to
+                be downloaded.
+    output_folder: the folder to which the specified files should be downloaded.
+
+  This scripts expects that its execution is done on a machine where the
+  credentials are correctly setup to obtain the required permissions for
+  downloading files from the specified GCS buckets.
+"""
+
+import argparse
+import ntpath
+import os
+import subprocess
+import sys
+
+
+def main():
+
+  parser = argparse.ArgumentParser()
+  parser.add_argument('-f', '--files',
+                      help='File specifying files to be downloaded .')
+  parser.add_argument(
+      '-o', '--output_folder',
+      help='Folder where specified files should be downloaded .')
+
+  if len(sys.argv) < 3:
+    parser.print_help()
+    sys.exit(1)
+
+  args = parser.parse_args()
+  if not args.files or not args.output_folder:
+    parser.print_help()
+    sys.exit(1)
+
+  # Loop through lines in input file specifying source file locations.
+  with open(args.files) as f:
+    for line in f:
+      # Copy the file to the output folder, with same name as source file.
+      output_file = os.path.join(args.output_folder, ntpath.basename(line))
+      # Download specified file from GCS.
+      cp_cmd = ['gsutil cp %s %s' % (line, output_file)]

[luqui, 2015/07/15 18:00:51]

1. this should be gsutil.py.

2. the arguments should be separated, i.e.

   cp_cmd = ['gsutil.py', 'cp', line, output_file]

otherwise it's looking for an executable file named "gsutil cp ...".

[luqui, 2015/07/15 18:02:07]

Oh I see, you have shell=True, so (2) isn't necessary.  But really I think you
should do it the way I suggest without shell=True.

+      try:
+        subprocess.check_output(cp_cmd, stderr=subprocess.STDOUT,
+                                shell=True)
+      except subprocess.CalledProcessError, e:
+        print e.output
+        sys.exit(1)
+
+if __name__ == '__main__':
+  main()