Fix compositor-touch-hit-rects.html

Test do not run, because "return" is not allowed at top level
(syntax error).

BUG=

Review URL: https://codereview.chromium.org/540613004

git-svn-id: svn://svn.chromium.org/blink/trunk@181550 bbb929c8-8fbe-4397-9dbb-9b2b20218538