Add stub for assigning media session to media elements

Introduces a partial IDL interface for HTMLMediaElement containing an
optional media session attribute implemented as a supplement to media
elements.

BUG=497735

Review URL: https://codereview.chromium.org/1217743003

git-svn-id: svn://svn.chromium.org/blink/trunk@198272 bbb929c8-8fbe-4397-9dbb-9b2b20218538
11 files changed
tree: 4048d182c09a7a3a3ea15631a10734dce707cd0f
  1. third_party/