Unship MediaController by making it an experimental runtime-enabled feature

LayoutTests/virtual/stable/webexposed/event-target-in-prototype-expected.txt

 Check that interfaces inherit from EventTarget
 
 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
 
 
 PASS EventSource.prototype.__proto__ is EventTarget.prototype
 PASS FileReader.prototype.__proto__ is EventTarget.prototype
-PASS MediaController.prototype.__proto__ is EventTarget.prototype
+FAIL MediaController.prototype.__proto__ should be [object Object]. Threw exception ReferenceError: MediaController is not defined

[acolwell GONE FROM CHROMIUM, 2014/04/28 15:52:14]

This doesn't seem right. This is the only FAIL in this file. Why is
MediaController still being tested if it is experimental? Are there no other
experimental EventTargets?

[philipj_slow, 2014/04/28 16:28:18]

There probably are, but event-target-in-prototype.html is simply a list of
interfaces. I could try to rewrite the test to iterate and test all properties
on window, or is there something else I could do?

 PASS MediaSource.prototype.__proto__ is EventTarget.prototype
 PASS MessagePort.prototype.__proto__ is EventTarget.prototype
 PASS Node.prototype.__proto__ is EventTarget.prototype
 PASS Performance.prototype.__proto__ is EventTarget.prototype
 PASS SVGElementInstance.prototype.__proto__ is EventTarget.prototype
 PASS SharedWorker.prototype.__proto__ is EventTarget.prototype
 PASS WebSocket.prototype.__proto__ is EventTarget.prototype
 PASS Window.prototype.__proto__ is EventTarget.prototype
 PASS Worker.prototype.__proto__ is EventTarget.prototype
 PASS AudioContext.prototype.__proto__ is EventTarget.prototype
 PASS successfullyParsed is true
 
 TEST COMPLETE