Please file a bug upstream at https://github.com/y-256/libdivsufsort/issues and possibly send them a pull request.

Oh so that's what upstream bug means. Should it be:
- Framed in terms of checklicenses.py?
- Or some sort of "may we use your code" request?
- Or "FYI we plan to use your code, thanks!"?

See  bug 472816  and  bug 573341  for examples where we asked other projects to add license headers. If the project requires more information, please explain checklicenses.py is actually a wrapper around Debian's licensecheck.pl [1] and it checks copyright on a per-file basis.

[1] https://wiki.debian.org/CopyrightReviewTools

The original source files have MIT license already though:
https://github.com/y-256/libdivsufsort/blob/master/lib/divsufsort.c

Should I instead add licensecheck.pl to the Chromium CL?

If the original files have the license, and yours don't... who removed them? Why?

licensecheck.pl is already in the Chromium repo under third_party. I was simply given you more context about the tools.

I moved the common boilerplate to LICENSE file, and added reference to the file:

// For the terms under which this work may be distributed, please see
// the adjoining file "LICENSE".

So this is bad?  Maybe I should just paste back the boilerplate and see if it passes checklicenses.py?

Yes, please put the license back. You have shot yourself in the foot. :)

Ah nice, checklicenses.py passed once I paste the boilerplate back (in "//" form).  So I can now proceed without upstream CL?

Ya, please close this bug then. Pawel and I didn't realize you took out the license text. Since the original code already has the license text, its author will look at you funny, had you filed a bug with them.

Sounds good.  Closing the bug, thanks for your help!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4

commit d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4
Author: huangs <huangs@chromium.org>
Date: Wed Jul 27 16:07:51 2016

[Courgette] Add third-party library: libdivsufsort.

We wish to use third-party library libdivsufsort in Courgette to replace
QSufSort in Courgette-gen. This will reduce time and memory usage. This
CL focuses on adding libdivsufsort and tests. We will make the switch in
a follow-up CL.

Proposal: go/courgette-use-libdivsufsort
Code source: https://github.com/y-256/libdivsufsort

BUG= 631482 , 608885 

Review-Url: https://codereview.chromium.org/2156223002
Cr-Commit-Position: refs/heads/master@{#408141}

[modify] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/BUILD.gn
[modify] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/courgette.gyp
[add] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/third_party/divsufsort/LICENSE
[add] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/third_party/divsufsort/README.chromium
[add] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/third_party/divsufsort/divsufsort.cc
[add] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/third_party/divsufsort/divsufsort.h
[add] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/third_party/divsufsort/divsufsort_private.h
[add] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/third_party/divsufsort/divsufsort_unittest.cc
[add] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/third_party/divsufsort/sssort.cc
[add] https://crrev.com/d63dcb01c3a8fc30a840ce5aaab8ea5e6c9107e4/courgette/third_party/divsufsort/trsort.cc