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

services/media/framework/stages/stage.cc

Index: services/media/framework/stages/stage.cc
diff --git a/services/media/framework/stages/stage.cc b/services/media/framework/stages/stage.cc
index e46eead900b743b0aab2b42e511b0dc2c9783155..813da9bb00cdcad83ee31aa4bcd7450e96bfd0f2 100644
--- a/services/media/framework/stages/stage.cc
+++ b/services/media/framework/stages/stage.cc
@@ -9,15 +9,16 @@ namespace mojo {
 namespace media {
 
 Stage::Stage() :
-    prepared_(false),
     in_supply_backlog_(false),
     in_demand_backlog_(false) {}
 
 Stage::~Stage() {}
 
-bool Stage::Prepare(UpdateCallback update_callback) {
-  return false;
-}
+void Stage::UnprepareInput(size_t index) {}
+
+void Stage::UnprepareOutput(
+    size_t index,
+    const UpstreamCallback& callback) {}
 
 void Stage::Prime() {}