*** DO NOT LAND *** Attempt to understand Regions complexity

*** DO NOT LAND *** Attempt to understand Regions complexity

*** DO NOT LAND *** This patch attempts to understand exactly how
much code we have in Blink to support the CSS Regions feature
and where that code reaches.

This is definitely an incomplete patch as it does not include any
of the LayerFragment complexity which I did not attempt to untangle.

This patch builds and passes many layout tests (although obviously not the Regions or tests).

Hopefully this is a useful tool for allowing all of us to visualize
exactly the complexity cost of CSS Regions in the Blink codebase.

Git tells me that this diff removes 10,000 lines.
For context, Ohloh tells us that there are only 350,000 lines of C++ in all of Blink.

http://www.ohloh.net/p/chromium-blink/analyses/latest/languages_summary