mash: Change CastConfigDelegate to a mojoified CastConfigClient.

ash/public/interfaces/cast_config.mojom

+// Copyright 2016 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.
+
+module ash.mojom;
+
+struct CastSink {

[James Cook, 2016/11/30 22:16:38]

Can you document this? (I know the original is undocumented.)

[Elliot Glaysher, 2016/12/01 23:59:12]

I cannot. I don't know what it is.

+  string id;
+  string name;
+  string domain;
+};
+
+enum ContentSource {
+  UNKNOWN,
+  TAB,
+  DESKTOP
+};
+
+struct CastRoute {

[James Cook, 2016/11/30 22:16:38]

ditto

+  string id;
+  string title;
+
+  // Is the activity source this computer? ie, are we mirroring the display?
+  bool is_local_source = false;
+
+  // What is source of the content? For example, we could be DIAL casting a
+  // tab or mirroring the entire desktop.
+  ContentSource content_source = ContentSource.UNKNOWN;
+};
+
+struct SinkAndRoute {
+  CastSink sink;
+  CastRoute route;
+};
+
+// Interface implemented by ash to listen for when devices become available.
+interface CastConfigObserver {
+  // Invoked whenever there is new sink or route information available.
+  OnDevicesUpdated(array<SinkAndRoute> device);
+};
+
+// This delegate allows the UI code in ash, e.g. |TrayCastDetailedView|,
+// to access the cast system.
+//
+// TODO(erg): Eventually, this should no longer be exported by chrome, but
+// should be exported by a separate cast service.
+interface CastConfigClient {

[James Cook, 2016/11/30 22:16:38]

As mentioned in person, I think we should have an interface CastConfig with a
SetClient method that chrome uses to set itself as the CastConfigClient.

CastConfig could replace CastConfigObserver (just have chrome call
CastConfig::OnDeviceUpdated directly).

[Elliot Glaysher, 2016/12/01 23:59:13]

Done.

+  // Request fresh data from the backend. When the data is available, all
+  // registered observers will get called.
+  RequestDeviceRefresh();
+
+  // Initiate a casting session to |sink|.
+  CastToSink(CastSink sink);
+
+  // A user-initiated request to stop the given cast session.
+  StopCasting(CastRoute route);
+
+  // Observers are immediately notified of the current shelf states when added.

[James Cook, 2016/11/30 22:16:38]

shelf states?  system tray / system menu state?  some other state?

[Elliot Glaysher, 2016/12/01 23:59:12]

Done.

+  AddObserver(associated CastConfigObserver observer);
+};