How is chromium-browser package maintained on launchpad?

Hi,

I'm the maintainer of https://github.com/brightray/libchromiumcontent, which provides a shared library of Chromium's content module, and I'm trying to provide a PPA for it.

However I'm currently troubled on how to build it in launchpad, it seems that it is not allowed to access networking in PPA's build machine, and there is no official source tarball that includes source code of Chromium and all its third party dependencies, so I looked in the chromium-browser package to try to find out how it is built, but only to find that it still stays on Chromium 15.

So can someone guide me how chromium-browser is built in PPA?

Thanks,
Cheng