Remove |remote| and |readonly| members of MediaStreamTrack.

Spec reference:
http://w3c.github.io/mediacapture-main/getusermedia.html#attributes-1

removal was in the February 22, 2016'.
[#321] Remove track attributes "remote" and "readonly" :
https://github.com/w3c/mediacapture-main/pull/321

Intent to Deprecate and Remove :
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/d20ECb2sWzI

BUG=598704

Review-Url: https://codereview.chromium.org/2425703002
Cr-Commit-Position: refs/heads/master@{#452851}
43 files changed