Blink implementation of PushManager#hasPermission()

public/platform/WebPushPermissionCallback.h

+// 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.
+
+#ifndef WebPushPermissionCallback_h
+#define WebPushPermissionCallback_h
+
+#include "WebPushPermissionStatus.h"
+
+// Interface to be used by the embedder in order
+// to inform Blink when once the permission status for push has been checked.
+namespace blink {
+
+class WebPushPermissionCallback {

[Mike West, 2014/10/27 15:32:11]

I don't think you need a whole class for this. What can't you do with
`WebCallbacks<WebPushPermissionStatus>`?

[Miguel Garcia, 2014/10/28 11:07:00]

Peter had the same comment, in the end we agreed that this was easier since
WebCallbacks expands the onSuccess method to onSuccess(S*) which for an S of
type enum seems like an overkill to pass a pointer.

[Mike West, 2014/10/28 11:23:35]

Easier is relative. Introducing another callback type with a very similar
signature that doesn't quite use the existing framework is a bit confusing.
Perhaps we could add a `WebCallbacks<enum, enum>` variant? You're probably not
the only callback with that use case; I know some of the CredentialManager code
could use the same.

On that note...

+public:
+    virtual ~WebPushPermissionCallback() { }
+
+    // Called if the embedder is able to check the status of the push permission.
+    virtual void onSuccess(WebPushPermissionStatus) = 0;
+
+    // Called if for some reason the status of the push permission cannot be checked.
+    virtual void onError() = 0;

[Mike West, 2014/10/28 11:23:35]

Are you sure you're not going to need to pass any error state down from the
embedder when the status can't be checked? Perhaps it's worth putting a
failure-types enum together as well.

[Miguel Garcia, 2014/10/28 13:59:21]

So right now the spec does not really pass any arguments with the kind of error
you got. I think with the new typedef I just built we should be able to upgrade
it easily if I need a new enum.

+};
+
+} // namespace blink
+#endif // WebPushPermissionCallback_h