Support receiving GrowableObjectArray on native ports

runtime/vm/dart_api_message.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_DART_API_MESSAGE_H_
 #define VM_DART_API_MESSAGE_H_
 
 #include "vm/dart_api_state.h"
 #include "vm/snapshot.h"
 
 namespace dart {
 
 // Use this C structure for reading internal objects in the serialized
 // data. These are objects that we need to process in order to
 // generate the Dart_CObject graph but that we don't want to expose in
 // that graph.
 // TODO(sjesse): Remove this when message serialization format is
 // updated.
 struct Dart_CObject_Internal : public Dart_CObject {
   enum Type {
     kTypeArguments = Dart_CObject::kNumberOfTypes,
     kDynamicType,
   };
 };
 
 
 // Reads a message snapshot into a C structure.
 class ApiMessageReader : public BaseReader {
  public:
+  // The allocator passed is used to allocate memory for the C structure used
+  // to represent the message snapshot. This allocator must keep track of the
+  // memory allocated as there is no way to run through the resulting C
+  // structure and free the individual pieces. Using a zone based allocator is
+  // recommended.
   ApiMessageReader(const uint8_t* buffer, intptr_t length, ReAlloc alloc);
   ~ApiMessageReader() { }
 
   Dart_CObject* ReadMessage();
 
  private:
   class BackRefNode {
    public:
     BackRefNode(Dart_CObject* reference, DeserializeState state)
         : reference_(reference), state_(state) {}
@@ skipping 115 matching lines @@
   Dart_CObject** forward_list_;
   intptr_t forward_list_length_;
   intptr_t forward_id_;
 
   DISALLOW_COPY_AND_ASSIGN(ApiMessageWriter);
 };
 
 }  // namespace dart
 
 #endif  // VM_DART_API_MESSAGE_H_