The chromium mirror of harfbuzz which can be browsed at https://chromium.googlesource.com/external/github.com/harfbuzz/harfbuzz/  was created without mirroring the upstream tags as it wasn't thought that they would be useful. It turns out that they are quite useful in conjunction with 'git describe' and properly updating README.chromium. This was originally offered as an option at https://bugs.chromium.org/p/chromium/issues/detail?id=816559#c9 but was not done at the time. Since it turns out that the upstream tags are useful, this is a request to mirror the upstream tags.

I think what we want is to add to the current

      refspec: <
        source: "refs/heads/*"
        destination: "refs/heads/upstream/*"
      >

source: "refs/tags/*"
destination: "refs/tags/upstream/*"