Sync the Presentation API interfaces with the spec

Source/modules/presentation/Presentation.idl

 // 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.
 
 // https://w3c.github.io/presentation-api/#navigatorpresentation
 
+// TODO(philipj): This interface is named NavigatorPresentation in the spec:
+// https://github.com/w3c/presentation-api/issues/137
 [
     GarbageCollected,
     RuntimeEnabled=Presentation
 ] interface Presentation : EventTarget {
-    readonly attribute PresentationSession? session;
-
-    [CallWith=ScriptState] Promise<PresentationSession> startSession(DOMString presentationUrl, [Default=Undefined] optional DOMString presentationId);
-    [CallWith=ScriptState] Promise<PresentationSession> joinSession(DOMString presentationUrl, [Default=Undefined] optional DOMString presentationId);
-
+    // This API used by controlling browsing context.
+    // TODO(philipj): The |presentationId| argument is not in the spec.

[whywhat, 2015/07/07 13:00:07]

https://codereview.chromium.org/1209423005/

[philipj_slow, 2015/07/07 13:18:31]

Did you paste the wrong link?

[whywhat, 2015/07/07 13:53:58]

Yes, I meant: https://codereview.chromium.org/1208083004

[philipj_slow, 2015/07/07 14:31:02]

I see. There will be conflicts here anyway so I'll just leave this to be removed
in a few days time :)

+    [CallWith=ScriptState] Promise<PresentationSession> startSession(DOMString url, [Default=Undefined] optional DOMString presentationId);
+    // TODO(philipj): The |presentationId| argument should not be optional.
+    [CallWith=ScriptState] Promise<PresentationSession> joinSession(DOMString url, [Default=Undefined] optional DOMString presentationId);
+    // TODO(philipj): The |url| argument is ultimately unused.

[whywhat, 2015/07/07 13:00:07]

This was only landed yesterday: https://codereview.chromium.org/1222623003

[philipj_slow, 2015/07/07 13:18:31]

Do you think that the URL argument will actually be used for something? Please
comment on https://github.com/w3c/presentation-api/issues/138 if I'm talking
crazy.

[philipj_slow, 2015/07/07 14:31:02]

I'll revert this TODO, it's not actionable until the spec changes, if it does.

+    [CallWith=ScriptState] Promise<PresentationAvailability> getAvailability(DOMString url);
     attribute EventHandler ondefaultsessionstart;
 
-    [CallWith=ScriptState] Promise<PresentationAvailability> getAvailability(DOMString presentationUrl);
+    // This API used by presenting browsing context.
+    // TODO(philipj): The spec has |getSession()| |getSessions()| instead.
+    readonly attribute PresentationSession? session;
+    // TODO(philipj): attribute EventHandler onsessionavailable;
 };