Sync "restrained media controller" with the spec

https://www.w3.org/Bugs/Public/show_bug.cgi?id=25429

The spec comments were already in sync.

BUG=417232

Review URL: https://codereview.chromium.org/262463003

git-svn-id: svn://svn.chromium.org/blink/trunk@182768 bbb929c8-8fbe-4397-9dbb-9b2b20218538
3 files changed
tree: a5772d977c7c8809f1ebdf3be0f850ef62692593
  1. third_party/