Replace iv().empty() to is_encrypted().

It makes better readability.

Review-Url: https://codereview.chromium.org/2489503002
Cr-Commit-Position: refs/heads/master@{#431217}

AUTHORS

@@ -591,6 +591,7 @@ Saikrishna Arcot <saiarcot895@gmail.com>
 Salvatore Iovene <salvatore.iovene@intel.com>
 Sam Larison <qufighter@gmail.com>
 Sam McDonald <sam@sammcd.com>
+Sanggi Hong <sanggi.hong11@gmail.com>
 Sanghee Lee <sanghee.lee1992@gmail.com>
 Sanghyun Park <sh919.park@samsung.com>
 Sanghyup Lee <sh53.lee@samsung.com>

media/cdm/aes_decryptor.cc

@@ -463,8 +463,7 @@ void AesDecryptor::Decrypt(StreamType stream_type,
   CHECK(encrypted->decrypt_config());
 
   scoped_refptr<DecoderBuffer> decrypted;
-  // An empty iv string signals that the frame is unencrypted.
-  if (encrypted->decrypt_config()->iv().empty()) {
+  if (!encrypted->decrypt_config()->is_encrypted()) {
     decrypted = DecoderBuffer::CopyFrom(encrypted->data(),
                                         encrypted->data_size());
   } else {

media/filters/decrypting_demuxer_stream.cc

@@ -235,8 +235,7 @@ void DecryptingDemuxerStream::DecryptBuffer(
   }
 
   DCHECK(buffer->decrypt_config());
-  // An empty iv string signals that the frame is unencrypted.
-  if (buffer->decrypt_config()->iv().empty()) {
+  if (!buffer->decrypt_config()->is_encrypted()) {
     DVLOG(2) << "DoDecryptBuffer() - clear buffer.";
     scoped_refptr<DecoderBuffer> decrypted = DecoderBuffer::CopyFrom(
         buffer->data(), buffer->data_size());