Add SubsampleEntry constructor.

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::vector<SubsampleEntry>& subsamples)
     : key_id_(key_id),
       iv_(iv),
       subsamples_(subsamples) {
   CHECK_GT(key_id.size(), 0u);
   CHECK(iv.size() == static_cast<size_t>(DecryptConfig::kDecryptionKeySize) ||
         iv.empty());
 }
 
 DecryptConfig::~DecryptConfig() {}
 
+bool DecryptConfig::Matches(const DecryptConfig& config) const {
+  if (key_id() != config.key_id() || iv() != config.iv() ||
+      subsamples().size() != config.subsamples().size()) {
+    return false;
+  }
+
+  for (size_t i = 0; i < subsamples().size(); ++i) {
+    if ((subsamples()[i].clear_bytes != config.subsamples()[i].clear_bytes) ||
+        (subsamples()[i].cypher_bytes != config.subsamples()[i].cypher_bytes)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 }  // namespace media