media config: expand is_encrypted to a struct.

media/filters/source_buffer_stream.cc

Index: media/filters/source_buffer_stream.cc
diff --git a/media/filters/source_buffer_stream.cc b/media/filters/source_buffer_stream.cc
index e03a8c38ab8e92d920fc73ac501b2ca38d67af38..05f23379ddcd07a9cf365ba6d8653ecedd2ecd62 100644
--- a/media/filters/source_buffer_stream.cc
+++ b/media/filters/source_buffer_stream.cc
@@ -1476,7 +1476,8 @@ bool SourceBufferStream::UpdateAudioConfig(const AudioDecoderConfig& config) {
     return false;
   }
 
-  if (audio_configs_[0].is_encrypted() != config.is_encrypted()) {
+  if (!audio_configs_[0].encryption_scheme().Matches(
+          config.encryption_scheme())) {
     MEDIA_LOG(ERROR, media_log_) << "Audio encryption changes not allowed.";
     return false;
   }
@@ -1507,7 +1508,8 @@ bool SourceBufferStream::UpdateVideoConfig(const VideoDecoderConfig& config) {
     return false;
   }
 
-  if (video_configs_[0].is_encrypted() != config.is_encrypted()) {
+  if (!video_configs_[0].encryption_scheme().Matches(
+          config.encryption_scheme())) {
     MEDIA_LOG(ERROR, media_log_) << "Video encryption changes not allowed.";
     return false;
   }