Update plugin/plugin-javascript-access.html now that the test plugin has moved

BUG=331302
TBR=ojan@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/163613008

git-svn-id: svn://svn.chromium.org/blink/trunk@167188 bbb929c8-8fbe-4397-9dbb-9b2b20218538