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

services/media/framework/packet.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 "base/logging.h"
-#include "services/media/framework/allocator.h"
 #include "services/media/framework/packet.h"
+#include "services/media/framework/payload_allocator.h"
 
 namespace mojo {
 namespace media {
 
 class PacketImpl : public Packet {
  public:
   PacketImpl(
       int64_t presentation_time,
       uint64_t duration,
       bool end_of_stream,
-      uint64_t size,
+      size_t size,
       void* payload,
-      Allocator* allocator) :
+      PayloadAllocator* allocator) :
       presentation_time_(presentation_time),
       duration_(duration),
       end_of_stream_(end_of_stream),
       size_(size),
       payload_(payload),
       allocator_(allocator) {
     DCHECK((size == 0) == (payload == nullptr));
   }
 
   ~PacketImpl() override {};
 
   int64_t presentation_time() const override { return presentation_time_; }
 
   uint64_t duration() const override { return duration_; }
 
   bool end_of_stream() const override { return end_of_stream_; }
 
-  uint64_t size() const override { return size_; }
+  size_t size() const override { return size_; }
 
   void* payload() const override { return payload_; }
 
  protected:
   void Release() override {
     if (payload_ != nullptr && allocator_ != nullptr) {
       DCHECK(allocator_);
       allocator_->ReleasePayloadBuffer(size_, payload_);
     }
     delete this;
   }
 
  private:
   int64_t presentation_time_;
   uint64_t duration_;
   bool end_of_stream_;
-  uint64_t size_;
+  size_t size_;
   void* payload_;
-  Allocator* allocator_;
+  PayloadAllocator* allocator_;
 };
 
 // static
 PacketPtr Packet::Create(
     int64_t presentation_time,
     uint64_t duration,
     bool end_of_stream,
-    uint64_t size,
+    size_t size,
     void* payload,
-    Allocator* allocator) {
+    PayloadAllocator* allocator) {
   DCHECK(payload == nullptr || allocator != nullptr);
   return PacketPtr(new PacketImpl(
       presentation_time,
       duration,
       end_of_stream,
       size,
       payload,
       allocator));
 }
 
 // static
 PacketPtr Packet::CreateNoAllocator(
     int64_t presentation_time,
     uint64_t duration,
     bool end_of_stream,
-    uint64_t size,
+    size_t size,
     void* payload) {
   return PacketPtr(new PacketImpl(
       presentation_time,
       duration,
       end_of_stream,
       size,
       payload,
       nullptr));
 }
 
 // static
 PacketPtr Packet::CreateEndOfStream(int64_t presentation_time) {
   return PacketPtr(new PacketImpl(
       presentation_time,
       0, // duration
       true, // end_of_stream
       0, // size
       nullptr, // payload
       nullptr)); // allocator
 }
 
 }  // namespace media
 }  // namespace mojo