[Presentation API] Additional plumbing for PresentationServiceImpl.

content/common/presentation/presentation_service.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.
 
 module presentation;
 
 import "presentation_session.mojom";
 
 struct PresentationSessionInfo {
-    PresentationSession session;
     string url;
     string id;
 };
 
 enum PresentationErrorType {
     NO_AVAILABLE_SCREENS,
     SESSION_REQUEST_CANCELLED,
     NO_PRESENTATION_FOUND,
     UNKNOWN,
 };
 
 struct PresentationError {
-    PresentationErrorType errorType;
+    PresentationErrorType error_type;
     string message;
 };
 
 interface PresentationService {
     // Called when the frame sets or changes the default presentation URL or
     // presentation ID.
     SetDefaultPresentationURL(
         string default_presentation_url,
         string? default_presentation_id);
 
     // Returns the last screen availability state if it’s changed since the last
     // time the method was called. The client has to call this method again when
     // handling the result (provided via Mojo callback) to get the next update
     // about the availability status.
     // May start discovery of the presentation screens. The implementation might
     // stop discovery once there are no active calls to GetScreenAvailability.
     // |presentation_url| can be specified to help the implementation to filter
     // out incompatible screens.
-    GetScreenAvailability(string? presentation_url) => (bool available);
+    GetScreenAvailability(string? presentation_url) =>
+        (string? presentation_url, bool available);
 
     // Called when the frame no longer listens to the
     // |availablechange| event.
     OnScreenAvailabilityListenerRemoved(string? presentation_url);
 
     // Called when the renderer is ready to receive the browser initiated
     // session. If the default session is started by the embedder before this
     // call, the embedder may queue it and run the callback when the call is
     // performed.
     ListenForDefaultSessionStart()
@@ skipping 11 matching lines @@
     // UA will generate the presentation id.
     StartSession(string presentation_url, string? presentation_id)
         => (PresentationSessionInfo? sessionInfo, PresentationError? error);
 
     // Called when joinSession() is called by the frame. The result callback
     // works the same as for the method above. JoinSession will join a known
     // session (i.e. when the page navigates or the user opens another tab)
     // silently and without user action.
     JoinSession(string presentation_url, string? presentation_id)
         => (PresentationSessionInfo? sessionInfo, PresentationError? error);
-};
+};