GitLab

In the current implementation, MessagePort does not support sending an
ArrayBuffer as a transferable object yet and unexpectedly loses the buffer
without any warning.

BUG=334408

Review URL: https://codereview.chromium.org/1301953002

git-svn-id: svn://svn.chromium.org/blink/trunk@200832 bbb929c8-8fbe-4397-9dbb-9b2b20218538