Unflake inspector-protocol/debugger/debugger-pause-dedicated-worker-loop.html

After posting a message to worker wait for reply before sending Runtime.evaluate request.

Added try/catch block into the worker script to disable optimizations for the hot function (v8 is failing to break in the optimized loop at the moment).

BUG=None
R=loislo@chromium.org

Review URL: https://codereview.chromium.org/333933007

git-svn-id: svn://svn.chromium.org/blink/trunk@176983 bbb929c8-8fbe-4397-9dbb-9b2b20218538