Plumbing from WebPresentationClient to the Presentation Mojo service for

content/common/presentation_session.mojom

+// Copyright 2014 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 presentation;
+
+// PresentationSession represents an interface between the page and one of its
+// presentations on the second screen. See the Presentation API for more details
+// about the API.
+[Client=PresentationSessionClient]
+interface PresentationSession {

[Peter Beverloo, 2015/01/07 15:13:01]

If you prune the unused methods in the other .mojom file, we can avoid adding
this entire module right now.

[whywhat, 2015/01/07 18:02:59]

Done.

+  /* PresentationSession idl */
+
+  // when onstatechange listener is added;
+  // might cause the event fired with the initial state change
+  StateChangeListenerAdded();
+
+  // when onstatechange listener is removed;
+  // might close the session?
+  StateChangeListenerRemoved();
+
+  // when onmessage listener is added;
+  // might open the communication channel
+  MessageListenerAdded();
+
+  // when onmessage listener is removed;
+  // might close the communication channel?
+  MessageListenerRemoved();
+
+  // when postMessage() is called
+  PostMessage(string message);
+
+  // when close() is called
+  CloseSession();
+};
+
+interface PresentationSessionClient {
+  // When to fire onstatechange event
+  SessionStateChanged(string new_state);
+
+  // When to fire onmessage event
+  SessionMessageReceived(string message);
+};