Since you should be able to build Chromium browser on any reasonably modern Linux distribution, can we assume that you should be able to build it onto Android ?
Yes. Actually it was the other way around. The Android web browser serve as startup for the google chrome browser
It is possible, there would be tons of restrictions.
According to this source ( sept 2008 )
Google co-founder, Sergey Brin revealed a few interesting tidbits about the Chrome/Android connection
So, that was actually initially planned, but haven't quite happened yet. The two team ( Android browser and Chrome ) are very busy getting their own product ready.
It may be developed eventually by the open source community, but don't hold your breath.
Android doesn't have many of the same libs that you'd find in a modern Linux distribution, so I would suspect that it would take a lot of re-engineering to make it happen. Maybe it's possible, but I would be very surprised.
No, Android is not exactly a Linux distribution. It's based on a Linux kernel, but it doesn't include an X server nor other dependencies for building Chromium on Linux.
However the Android Browser is also based on WebKit and includes the V8 JavaScript engine.