Initial implementation of music manager private API.

chrome/common/extensions/api/music_manager_private.idl

Index: chrome/common/extensions/api/music_manager_private.idl
diff --git a/chrome/common/extensions/api/music_manager_private.idl b/chrome/common/extensions/api/music_manager_private.idl
new file mode 100644
index 0000000000000000000000000000000000000000..5997d709261eb822b64803c721378bff773a169c
--- /dev/null
+++ b/chrome/common/extensions/api/music_manager_private.idl
@@ -0,0 +1,15 @@
+// Copyright 2013 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.
+
+[nodoc] namespace musicManagerPrivate {
+
+  callback GetDeviceIdCallback = void (DOMString device_id);
+
+  interface Functions {
+    // Returns an identifier stable across users and reboots.
+    //
+    // |callback| : Called with the stable identifier value.
+    static void getDeviceId(GetDeviceIdCallback callback);
+  };
+};