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

services/media/framework/metadata.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/media/framework/metadata.h"
 
 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,
     const std::string& album,
     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,
       album,
       publisher,
       genre,
       composer));
 }
 
 Metadata::Metadata(
     uint64_t duration_ns,
     const std::string& title,
     const std::string& artist,
     const std::string& album,
     const std::string& publisher,
     const std::string& genre,
     const std::string& composer) :
     duration_ns_(duration_ns),
     title_(title),
     artist_(artist),
     album_(album),
     publisher_(publisher),
     genre_(genre),
     composer_(composer) {}
 
 Metadata::~Metadata() {}
 
 }  // namespace media
 }  // namespace mojo