This tarball/subdirectory contains Chromium source files that, under normal
circumstances, are generated in the course of a (binary) build. Because the
generation process typically requires recent versions of build-dep packages
like bindgen and nodejs, it is prone to failure on Debian stable releases,
where those versions may not be available.

To avoid failed builds due to this, Debian has prepared these files in
advance, so that they can simply be copied into the build tree when needed
rather than the build trying (and failing) to generate them.

Some of the files are specific to an architecture (amd64/**, ppc64el/**
et al.); most are architecture-independent (indep/**). If you have a
fully-built Chromium tree that did not make use of these files, then you
can compare the pre-generated vs. normally-generated sets with e.g.

  $ diff -ru pre-gen/amd64 out/Release
  $ diff -ru pre-gen/indep out/Release

The BUILDINFO file, in deb-buildinfo(5) format, contains details of the
environment in which these files were generated.

To review the implementation of the pre-generated source mechanism, please
see the following files (not in this tarball/subdirectory):

  debian/deb_pre_gen.py
  debian/patches/debianization/pre-gen.patch
  debian/scripts/init-pre-gen.sh

If you do not wish to make use of pre-generated files in your Chromium
build, then simply delete the pre-gen/ subdirectory from the source tree.
(For completeness, you might also want to drop pre-gen.patch from the patch
series.) As long as you have recent-enough build dependencies installed,
the build will not be any worse off.
