Mojom updates for Motown.

mojo/services/media/common/interfaces/media_state.mojom

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+[DartPackage="mojo_services"]
+module mojo.media;
+
+// Expresses the overall state of a media component.

[jeffbrown, 2015/12/10 20:00:59]

Can we eliminate some of these states?  My experience has been that complexity
and bugs increase quadratically with the number of states that a client must be
aware of.

[dalesat, 2015/12/10 22:33:39]

I'd like to keep FAULT for the time being. I have different way of expressing
errors in the works, but I need FAULT until I can implement it. I've added a
TODO.

DISABLED and PREPARING can go.

+enum MediaState {
+  // Unable to function due to error. Fault details are provided elsewhere.
+  FAULT,
+
+  // Intentionally disabled.
+  DISABLED,
+
+  // Requires preparation in order to function.
+  UNPREPARED,
+
+  // Preparation underway.
+  PREPARING,
+
+  // Fully prepared, rate zero (paused).
+  PREPARED,

[jeffbrown, 2015/12/10 20:00:59]

How about calling this PAUSED?

[dalesat, 2015/12/10 22:33:39]

Done.

+
+  // Fully prepared, rate non-zero.
+  PLAYING,
+
+  // Stopped playing because end-of-stream was encountered.
+  ENDED
+};