SDK stuff: Add a script to download the mojom parser binary.

sdk_build/data/common/download_file_from_google_storage.py

Index: sdk_build/data/common/download_file_from_google_storage.py
diff --git a/sdk_build/data/common/download_file_from_google_storage.py b/sdk_build/data/common/download_file_from_google_storage.py
new file mode 100755
index 0000000000000000000000000000000000000000..28feb4d3db4d479e21aa9af637f5adaed03fee94
--- /dev/null
+++ b/sdk_build/data/common/download_file_from_google_storage.py
@@ -0,0 +1,68 @@
+#!/usr/bin/env python
+# Copyright 2016 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.
+
+#FIXME
+
+import argparse
+import hashlib
+import httplib
+import os
+import sys
+
+
+def _FatalError(message):
+  print >> sys.stderr, "%s: fatal error: %s" % (os.path.basename(sys.argv[0]),
+                                                message)
+
+
+def _DownloadFile(source):
+  """FIXME"""
+
+  try:
+    conn = httplib.HTTPSConnection("storage.googleapis.com")
+    conn.request("GET", "/" + source)
+    resp = conn.getresponse()
+    if resp.status != httplib.OK:
+      _FatalError("HTTP status: %s" % resp.reason)
+    data = resp.read()
+    conn.close()
+    return data
+  except httplib.HTTPException as e:
+    _FatalError("HTTP exception: %s" % str(e))
+
+
+def main():
+  parser = argparse.ArgumentParser(
+      description="Downloads a file from Google Cloud Storage.")
+  parser.add_argument("--sha1-hash", dest="sha1_hash",
+                      help="SHA-1 hash for the downloaded file")
+  parser.add_argument("--executable", action="store_true",
+                      help="make the downloaded file executable")
+  parser.add_argument("source", help="source path, including bucket name")
+  parser.add_argument("destination", help="destination path")
+  args = parser.parse_args()
+
+  bits = _DownloadFile(args.source)
+  if args.sha1_hash:
+    got_sha1_hash = hashlib.sha1(bits).hexdigest().lower()
+    expected_sha1_hash = args.sha1_hash.lower()
+    if got_sha1_hash != expected_sha1_hash:
+      _FatalError("SHA-1 hash did not match: got %s, expected %s" %
+                  (got_sha1_hash, expected_sha1_hash))
+
+  with open(args.destination, "wb") as f:
+    f.write(bits)
+
+  if args.executable:
+    curr_mode = os.stat(args.destination).st_mode
+    # Set the x bits (0111) where the r bits (0444) are set.
+    new_mode = curr_mode | ((curr_mode & 0444) >> 2)
+    os.chmod(args.destination, new_mode)
+
+  return 0
+
+
+if __name__ == "__main__":
+  sys.exit(main())