UserAgent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0

Steps to reproduce the problem:
1. Checkout Chromium source code
2. Generate source tarball with https://chromium.googlesource.com/chromium/tools/build/+/master/scripts/slave/recipe_modules/chromium/resources/export_tarball.py

What is the expected behavior?
The script should generate identical source tarballs in different environments (e.g. different machines or different checkout time), as long as they are using the same revision of the source code.

What went wrong?
The generated source tarballs are slightly different because different file ownership and file timestamps are encoded in the source tarball.

Did this work before? N/A 

Chrome version:   Channel: n/a
OS Version: 
Flash Version: 

The 'filter' parameter of TarFile.add() can be used to overwrite the ownership and timestamp of a TarInfo object, and thus generate deterministic source tarball in different environments.