Remove the checksum/HMAC code from the decryptor.

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 58 matching lines @@
   /**
    * Size in bytes of encrypted data in a subsample entry.
    */
   uint32_t cipher_bytes;
 };
 
 /**
  * The <code>PP_EncryptedBlockInfo</code> struct contains all the information
  * needed to decrypt an encrypted block.
  */
-[assert_size(256)]
+[assert_size(240)]
 struct PP_EncryptedBlockInfo {
   /**
    * Information needed by the client to track the block to be decrypted.
    */
   PP_DecryptTrackingInfo tracking_info;
 
   /**
    * Size in bytes of data to be discarded before applying the decryption.
    */
   uint32_t data_offset;
@@ skipping 10 matching lines @@
   uint8_t[64] key_id;
   uint32_t key_id_size;
 
   /**
    * Initialization vector of the block to be decrypted.
    */
   uint8_t[16] iv;
   uint32_t iv_size;
 
   /**
-   * Checksum of the block to be decrypted.
-   */
-  uint8_t[12] checksum;
-  uint32_t checksum_size;
-
-  /**
    * Subsample information of the block to be decrypted.
    */
   PP_DecryptSubsampleDescription[16] subsamples;
   uint32_t num_subsamples;
 };
 
 /**
  * The <code>PP_DecryptResult</code> enum contains decryption and decoding
  * result constants.
  */
@@ skipping 24 matching lines @@
    * Result of the decryption (and/or decoding) operation.
    */
   PP_DecryptResult result;
 
   /**
    * 4-byte padding to make the size of <code>PP_DecryptedBlockInfo</code>
    * a multiple of 8 bytes. The value of this field should not be used.
    */
   uint32_t padding;
 };