Fix crashes after r155745

The following tests are crashing due to missing a frame() check.

- fast/dom/exception-no-frame-inline-script-crash.html
- fast/dom/ready-state-change-crash.html,webmidi/requestmidiaccess.html

This CL adds the frame() check.

TBR=mkwst@chromium.org,dominicc@chromium.org

Review URL: https://codereview.chromium.org/22401004

git-svn-id: svn://svn.chromium.org/blink/trunk@155754 bbb929c8-8fbe-4397-9dbb-9b2b20218538