These html pages can be executed by running cobalt and pointing the
--url parameter to the file in question. For example:
file:///cobalt/demos maps to the
src/out/<PLATFORM>/content/data/test/cobalt/demos directory, whose contents are copied from the
src/cobalt/demos/content source directory when
ninja cobalt_with_demos is run
To assist in running the html tests the interactive
html_test_runner.py in this directory.