http://shortn/_XzXUmMcDOk

It seems to be failing for the following repos:
components/feedback
net/tools/testserver
third_party/sqlite
third_party/tcmalloc/chromium
third_party/zlib

With errors like:

[I2016-12-15T01:46:25.334480+00:00 24997 139695573817152 infra.services.gsubtreed.gsubtreed:154] processing Ref(Repo('https://chromium.googlesource.com/chromium/src'), 'refs/branch-heads/2357')
error: refs/heads/master does not point to a valid object!
To https://chromium.googlesource.com/a/chromium/src/third_party/zlib
 ! [rejected]                  79db2186a80dc306c3c0b0a400190d52446de8c7 -> master (fetch first)
error: failed to push some refs to 'https://chromium.googlesource.com/a/chromium/src/third_party/zlib'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

For each one of these I also notice a message:
[W2016-12-15T01:52:55.414197+00:00 24997 139695573817152 infra.services.gsubtreed.gsubtreed:198] path 'third_party/zlib' was deleted in commit Commit(Repo('https://chromium.googlesource.com/chromium/src'), '5d4451ebf298d9d71f716cc0135f465cec41fcd0')

Note that that commit was made in 2011: https://chromium.googlesource.com/chromium/src/+/5d4451ebf298d9d71f716cc0135f465cec41fcd0