Load CMA backend from shared library

chromecast/media/cma/base/decoder_buffer_adapter.cc

Index: chromecast/media/cma/base/decoder_buffer_adapter.cc
diff --git a/chromecast/media/cma/base/decoder_buffer_adapter.cc b/chromecast/media/cma/base/decoder_buffer_adapter.cc
index ed8a779b5c0eb5e0f331718ab772a91ee71c3599..10ffddcce061f66a7aa53c8ba83da3d2755a0e22 100644
--- a/chromecast/media/cma/base/decoder_buffer_adapter.cc
+++ b/chromecast/media/cma/base/decoder_buffer_adapter.cc
@@ -4,6 +4,8 @@
 
 #include "chromecast/media/cma/base/decoder_buffer_adapter.h"
 
+#include "chromecast/media/cma/base/cast_decrypt_config_impl.h"
+#include "chromecast/public/media/cast_decrypt_config.h"
 #include "media/base/decoder_buffer.h"
 
 namespace chromecast {
@@ -31,7 +33,7 @@ base::TimeDelta DecoderBufferAdapter::timestamp() const {
   return buffer_->timestamp();
 }
 
-void DecoderBufferAdapter::set_timestamp(const base::TimeDelta& timestamp) {
+void DecoderBufferAdapter::set_timestamp(base::TimeDelta timestamp) {
   buffer_->set_timestamp(timestamp);
 }
 
@@ -47,8 +49,13 @@ size_t DecoderBufferAdapter::data_size() const {
   return buffer_->data_size();
 }
 
-const ::media::DecryptConfig* DecoderBufferAdapter::decrypt_config() const {
-  return buffer_->decrypt_config();
+const CastDecryptConfig* DecoderBufferAdapter::decrypt_config() const {
+  if (buffer_->decrypt_config() && !decrypt_config_) {
+    const ::media::DecryptConfig* config = buffer_->decrypt_config();
+    decrypt_config_.reset(new CastDecryptConfigImpl(*config));
+  }
+
+  return decrypt_config_.get();
 }
 
 bool DecoderBufferAdapter::end_of_stream() const {