Add SharedWorkerMessageFilter for the embedded SharedWorker.

It will be used instead of WorkerMessageFilter when "enable-embedded-shared-worker" is set.

BUG=327256

Review URL: https://codereview.chromium.org/166273002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251334 0039d316-1c4b-4281-b951-d872f2087c98
5 files changed