Make MediaQueryEvaluator(bool) constructor explicit.
https://bugs.webkit.org/show_bug.cgi?id=107620

Reviewed by Hajime Morita.

No new tests: no change in behavior.

* css/MediaQueryEvaluator.h:
(MediaQueryEvaluator):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140503 268f45cc-cd09-0410-ab3c-d52691b4dbfc