Introduce the Blink NotificationService, move permission checks there

third_party/WebKit/public/platform/modules/notifications/notification_service.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 blink.mojom;
+
+import "third_party/WebKit/public/platform/modules/permissions/permission_status.mojom";
+
+// Service through which Blink can request notifications to be shown, closed or
+// retrieved from the embedder.
+interface NotificationService {
+  // Synchronously retrieves the permission status for |origin|. Required to
+  // be synchronous due to the Notification.permission JavaScript getter.
+  [Sync] GetPermissionStatus(string origin) => (PermissionStatus status);

[Sam McNally, 2016/05/06 05:14:09]

This seems like it belongs in PermissionService.

[Peter Beverloo, 2016/05/06 14:51:33]

Conceptually it does, but the notification permission checks go beyond what the
permission service (and back-ends) currently offer due to tying in to
extensions. This is a refactoring we will do later.

[mlamouri (slow - plz ping), 2016/05/07 12:55:25]

I don't think extensions is a problem to use the permission service. The
permission service will ultimately call the chrome's PermissionManager which
will then call the notification permission context which will deal with the
extension stuff. Last I checked, geolocation hooks into extensions too.

This said, I would prefer to avoid adding this sync method to the permission
service because it's only used by notification code and I wouldn't want to
introduce this to the permission service with the risk of having new uses of it
and mostly, adding constraints to permission code coming from old notification
api debts.

+};