Add decoder de-initialize and reset to the Pepper CDM API.

ppapi/api/private/pp_content_decryptor.idl

 /* Copyright (c) 2012 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.
  */
 
 /**
  * The <code>PP_DecryptTrackingInfo</code> struct contains necessary information
  * that can be used to associate the decrypted block with a decrypt request
  * and/or an input block.
  */
@@ skipping 242 matching lines @@
   /**
    * Height of the video frame, in pixels.
    */
   int32_t height;
 
   /**
    * Information needed by the client to track the decrypted frame.
    */
   PP_DecryptTrackingInfo tracking_info;
 };
+
+/**
+ * <code>PP_StreamType</code> contains stream type constants.
+ */
+[assert_size(4)]
+enum PP_StreamType {
+  PP_STREAMTYPE_AUDIO = 0,
+  PP_STREAMTYPE_VIDEO = 1
+};