The headless-browser source is getting a bit unwieldy. The ordering of
class and method definitions is fragile; e.g. the application and web
view classes each require full definitions of each other. So it has
reached the point where it makes sense to give headless-browser some
better file structure.
To prepare for that, this patch simply moves its source to live along-
side the other browser chromes. This location is a bit better prepared
for creating more files, as the Utilities folder doesn't even have its
own CMakeLists.txt.
