Revert 149449 - Add support for v0.3 of the encrypted WebM specification.

media/base/decrypt_config.cc

 // 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.
 
 #include "media/base/decrypt_config.h"
 
 #include "base/logging.h"
 
 namespace media {
 
 DecryptConfig::DecryptConfig(const std::string& key_id,
                              const std::string& iv,
                              const std::string& checksum,
                              const int data_offset,
                              const std::vector<SubsampleEntry>& subsamples)
     : key_id_(key_id),
       iv_(iv),
       checksum_(checksum),
       data_offset_(data_offset),
       subsamples_(subsamples) {
   CHECK_GT(key_id.size(), 0u);
-  CHECK(iv.size() == static_cast<size_t>(DecryptConfig::kDecryptionKeySize) ||
-        iv.empty());
+  CHECK_EQ(iv.size(), static_cast<size_t>(DecryptConfig::kDecryptionKeySize));
   CHECK_GE(data_offset, 0);
 }
 
 DecryptConfig::~DecryptConfig() {}
 
 }  // namespace media