Load CMA backend from shared library

chromecast/media/cma/base/decoder_buffer_adapter.h

Index: chromecast/media/cma/base/decoder_buffer_adapter.h
diff --git a/chromecast/media/cma/base/decoder_buffer_adapter.h b/chromecast/media/cma/base/decoder_buffer_adapter.h
index 7c48ec8a40b7a1d10f0706b7ba66c21cbe8bac13..51186944109dbed077eb993cfd900895e9836be7 100644
--- a/chromecast/media/cma/base/decoder_buffer_adapter.h
+++ b/chromecast/media/cma/base/decoder_buffer_adapter.h
@@ -7,6 +7,7 @@
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "chromecast/media/cma/base/decoder_buffer_base.h"
 
 namespace media {
@@ -30,11 +31,11 @@ class DecoderBufferAdapter : public DecoderBufferBase {
   // DecoderBufferBase implementation.
   StreamId stream_id() const override;
   base::TimeDelta timestamp() const override;
-  void set_timestamp(const base::TimeDelta& timestamp) override;
+  void set_timestamp(base::TimeDelta timestamp) override;
   const uint8* data() const override;
   uint8* writable_data() const override;
   size_t data_size() const override;
-  const ::media::DecryptConfig* decrypt_config() const override;
+  const CastDecryptConfig* decrypt_config() const override;
   bool end_of_stream() const override;
 
  private:
@@ -42,6 +43,7 @@ class DecoderBufferAdapter : public DecoderBufferBase {
 
   StreamId stream_id_;
   scoped_refptr<::media::DecoderBuffer> const buffer_;
+  mutable scoped_ptr<CastDecryptConfig> decrypt_config_;
 
   DISALLOW_COPY_AND_ASSIGN(DecoderBufferAdapter);
 };