This folder contains GN binaries. They should be automatically downloaded from Google Storage by gclient runhooks for the current platform. To upload a file: python ~/depot_tools/upload_to_google_storage.py -b chromium-gn To download a file given a .sha1 file: python ~/depot_tools/download_from_google_storage.py -b chromium-gn -s .sha1 List the contents of GN's Google Storage bucket: python ~/depot_tools/third_party/gsutil/gsutil ls gs://chromium-gn/ To initialize gsutil's credentials: python ~/depot_tools/third_party/gsutil/gsutil config That will give a URL which you should log into with your web browser. The username should be the one that is on the ACL for the "chromium-gn" bucket (probably your @google.com address). Contact the build team for help getting access if necessary. Copy the code back to the command line util. Ignore the project ID (it's OK to just leave blank when prompted). gsutil documentation: https://developers.google.com/storage/docs/gsutil