Submitted tests for Shadow DOM

I have submitted the first few test cases for Shadow DOM from Google. These
test one narrow section of the spec, upper-boundary encapsulation [1].
Feedback is welcome.

The tests are at <
http://w3c-test.org/webapps/ShadowDOM/tests/submissions/Google/tests.html>.

Thanks to Art for guidance on organization and Philippe and Mike Smith for
helping me work out how to access the hg repository.

Dominic

[1] <
https://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/shadow/index.html#upper-boundary-encapsulation
>