media: Add mojo MediaPermission service

media/mojo/interfaces/media_permission.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 media.interfaces;
+
+// An interface to query media related permission checks and requests.
+interface MediaPermission {
+  enum Type {
+    PROTECTED_MEDIA_IDENTIFIER,
+    AUDIO_CAPTURE,
+    VIDEO_CAPTURE,
+  };
+
+  // Checks and returns whether |type| is permitted for |security_origion|
+  // without triggering user interaction (e.g. permission prompt). The result
+  // will be |false| if the permission has never been set.
+  HasPermission(Type type, string security_origin) => (bool granted);
+
+  // Requests and returns whether |type| is permitted for |security_origion|.
+  // This may trigger user interaction (e.g. permission prompt) if the
+  // permission has never been set.
+  RequestPermission(Type type, string security_origin) => (bool granted);
+};