Add a DEPS gclient hook to prune corrupt mockito remote.

webrtc/build/prune_third_party_mockito_origin.py

Index: webrtc/build/prune_third_party_mockito_origin.py
diff --git a/webrtc/build/prune_third_party_mockito_origin.py b/webrtc/build/prune_third_party_mockito_origin.py
new file mode 100644
index 0000000000000000000000000000000000000000..402f323e3f364fba5ecfb10908e89ca4485a2d8e
--- /dev/null
+++ b/webrtc/build/prune_third_party_mockito_origin.py
@@ -0,0 +1,33 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+# Used to work around an upstream bug (crbug.com/644722).
+# This file will be removed ASAP.
+
+import os
+import subprocess
+import sys
+
+# Path to the corrupt project.
+MOCKITO_CHECKOUT_PATH = 'src/third_party/mockito/src'
+
+
+def main():
+  # If this checkout exists, run `git remote prune origin` from it.
+  if os.path.isdir(MOCKITO_CHECKOUT_PATH):
+    subprocess.check_output(
+        ['git', 'remote', 'prune', 'origin'], cwd=MOCKITO_CHECKOUT_PATH)
+  else:
+    sys.stdout.write('{} does not exist!\n'.format(MOCKITO_CHECKOUT_PATH))
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())