Plumbing from WebPresentationClient to the Presentation Mojo service for

content/common/presentation_service.mojom

+// Copyright 2014 The Chromium Authors. All rights reserved.

[Peter Beverloo, 2015/01/07 15:13:00]

nit: 2015. Elsewhere too.

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

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+module presentation;
+
+import "content/common/presentation_session.mojom";
+
+[Client=PresentationServiceClient]
+interface PresentationService {

[Peter Beverloo, 2015/01/07 15:13:00]

Nothing provides this service yet, right? I very much prefer adding both sides
of {IPC, Mojo} communication in the same patch, even when it's very bare-bone.

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

Done.

+  /* NavigatorPresentation idl */
+
+  // when the default presentation url/id are parsed first and/or when the frame

[Peter Beverloo, 2015/01/07 15:13:00]

While I'm not the appropriate reviewer for Mojo stuff, I don't like how these
comments consistently lack grammar and capitals.

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

Done.

+  // changes at least one of the two.
+  SetDefaultPresentation(

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

This is not being used yet.

The same goes for DefaultPresentationListenerChanged, StartSession and
JoinSession.

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

Removed from this CL.

+      string default_presentation_url,
+      string? default_presenation_id);
+
+  // when ondefaultpresentationstarted listener added/removed;
+  // indicates if the frame is ready to handle the default presentation session
+  // started by the user agent or not
+  DefaultPresentationListenerChanged(bool is_present);
+
+  // when onavailablechange listener added;
+  // might start device discovery
+  AddDeviceAvailabilityListener();
+
+  // when onavailablechange listener removed;
+  // might stop device discovery
+  RemoveDeviceAvailabilityListener();
+
+  // when startSession() is called
+  // the result callback will return the presentation id (since 
+  // it can be provided by the UA) and the session identified to 
+  // use with the service going forward
+  StartSession(
+      string presentation_url,
+      string? presentation_id,
+      PresentationSession& session) => (bool success, string? error);
+
+  // when joinSession() is called; same result callback as above
+  JoinSession(
+      string presentation_url,
+      string? presentation_id,
+      PresentationSession& session) => (bool success, string? error);
+};
+
+interface PresentationServiceClient {
+  // When to fire onavailablechange event
+  DeviceAvailabilityChanged(bool available);
+
+  // When to fire ondefaultpresentation event
+  DefaultPresentationStarted(PresentationSession? session);
+};