Whitespace change. Remove blank lines.
Change test. Only use `WebKitCSSMatrix` if it's present.

`typeof WebKitCSSMatrix` returns `function` in Chrome 28. Unsure if this
is a change or if the original test was faulty.

Regardless, change the test to something sure to do what we mean.
Only compare against `WebKitCSSMatrix` if it's present.
Update JSClass submodule to latest commit.