media: Add MediaPermission interface and MediaPermissionDispatcher.

media/base/media_permission.h

+// 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.
+
+#ifndef MEDIA_BASE_MEDIA_PERMISSION_H_
+#define MEDIA_BASE_MEDIA_PERMISSION_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "media/base/media_export.h"
+
+class GURL;
+
+namespace media {
+
+// Interface to handle media related permission checks and requests.
+class MEDIA_EXPORT MediaPermission {
+ public:
+  typedef base::Callback<void(bool)> PermissionStatusCB;
+
+  enum Type {
+    PROTECTED_MEDIA_IDENTIFIER,
+  };
+
+  MediaPermission();
+  virtual ~MediaPermission();
+
+  // Checks whether |type| is permitted for |security_origion| without
+  // triggering user interaction (e.g. permission info bar). The status will be
+  // |false| if the permission has never been set.
+  virtual void HasPermission(

[ddorwin, 2015/01/26 23:33:46]

"Has" seems wrong here. To make the intent clear, perhaps it should be
SilentlyCheckPermission or something like that.

Oh, this is a name from the permission service. That's more okay then (assuming
the behaviors are the same).

[xhwang, 2015/01/27 00:01:58]

Acknowledged.

+      Type type,
+      const GURL& security_origin,
+      const PermissionStatusCB& permission_status_cb) = 0;
+
+  // Requests |type| permission for |security_origion|. This may trigger user
+  // interaction (e.g. permission info bar) if the permission has never been

[ddorwin, 2015/01/26 23:33:46]

nit: s/info bar/prompt/ (or request) to be more general and avoid rotting.

[xhwang, 2015/01/27 00:01:58]

Done.

+  // set.
+  virtual void RequestPermission(
+      Type type,
+      const GURL& security_origin,
+      const PermissionStatusCB& permission_status_cb) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MediaPermission);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_MEDIA_PERMISSION_H_