Implement navigator.requestMediaKeySystemAccess()

Source/modules/encryptedmedia/NavigatorRequestMediaKeySystemAccess.idl

Index: Source/modules/encryptedmedia/NavigatorRequestMediaKeySystemAccess.idl
diff --git a/Source/modules/encryptedmedia/NavigatorRequestMediaKeySystemAccess.idl b/Source/modules/encryptedmedia/NavigatorRequestMediaKeySystemAccess.idl
new file mode 100644
index 0000000000000000000000000000000000000000..daed7eebcf6bf560daeb89902973318194ffb927
--- /dev/null
+++ b/Source/modules/encryptedmedia/NavigatorRequestMediaKeySystemAccess.idl
@@ -0,0 +1,11 @@
+// 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.
+
+// https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#requestmediakeysystemaccess
+
+[
+    RuntimeEnabled=EncryptedMedia
+] partial interface Navigator {
+    [CallWith=ScriptState] Promise requestMediaKeySystemAccess(DOMString keySystem, optional sequence<MediaKeySystemOptions> supportedConfigurations);
+};