I can appreciate that you're unfamiliar with the build and dependency management tools used by Chromium and related projects. However, it's disingenuous to imply that somehow the project is any less public or open because of that.
Some dependencies are pulled in and set-up by the checkout scripts, which is not an unusual degree of complexity for a large group of projects with such broad dependencies. It's all clearly documented and everything you need to know to checkout, build, and contribute code is linked from right here: http://www.chromium.org/nativeclient
I think you pretty much proved my point. NaCL is a sandbox, the very thing that should have the cleanest, clearest delineated lines. But there's no standalone version, no stub version. And you seemingly need a PhD in Chromium to even find the source much less get it working in anything else.
I guess Mozilla is unusually capable then because their download link is right here:
So you're working on Chromium and think navigating a buildbot to get python scripts that download from a private svn is not unusual... ok fine, but don't be surprised if people don't want to touch it (or even can figure out how to). I certainly understand better now why Mozilla would rather just drop Flash support.
Some dependencies are pulled in and set-up by the checkout scripts, which is not an unusual degree of complexity for a large group of projects with such broad dependencies. It's all clearly documented and everything you need to know to checkout, build, and contribute code is linked from right here: http://www.chromium.org/nativeclient