Motown: Remove LPCM optimizations, fix prepare, add flush, add ActiveMultistreamSink model/stage

services/media/framework/metadata.cc

Index: services/media/framework/metadata.cc
diff --git a/services/media/framework/metadata.cc b/services/media/framework/metadata.cc
index d62b4b78f0a996dd1e0ceab8add1e3f5d9e57ea0..bd39df822b75e46281589c666c2e3e0f68e87a49 100644
--- a/services/media/framework/metadata.cc
+++ b/services/media/framework/metadata.cc
@@ -8,7 +8,7 @@ namespace mojo {
 namespace media {
 
 // static
-MetadataPtr Metadata::Create(
+std::unique_ptr<Metadata> Metadata::Create(
     uint64_t duration_ns,
     const std::string& title,
     const std::string& artist,
@@ -16,7 +16,7 @@ MetadataPtr Metadata::Create(
     const std::string& publisher,
     const std::string& genre,
     const std::string& composer) {
-  return MetadataPtr(new Metadata(
+  return std::unique_ptr<Metadata>(new Metadata(
       duration_ns,
       title,
       artist,