Add support for lists and backward references when decoding a message to a Dart_CObject object

runtime/vm/snapshot.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_SNAPSHOT_H_
 #define VM_SNAPSHOT_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/bitfield.h"
@@ skipping 431 matching lines @@
   // Allocates a Dart_CObject object for string data on the C heap.
   Dart_CObject* AllocateDartCObjectString(intptr_t length);
   // Allocates a C array of Dart_CObject objects on the C heap.
   Dart_CObject* AllocateDartCObjectArray(intptr_t length);
 
   intptr_t LookupInternalClass(intptr_t class_header);
   Dart_CObject* ReadInlinedObject(intptr_t object_id);
   Dart_CObject* ReadObjectImpl(intptr_t header);
   Dart_CObject* ReadIndexedObject(intptr_t object_id);
 
+  // Add object to backward references.
+  void AddBackwardReference(intptr_t id, Dart_CObject* obj);
+
   Dart_CObject_Internal* AsInternal(Dart_CObject* object) {
     ASSERT(object->type >= Dart_CObject::kNumberOfTypes);
     return reinterpret_cast<Dart_CObject_Internal*>(object);
   }
 
   ReAlloc alloc_;
+  GrowableArray<Dart_CObject*> backward_references_;
 
   Dart_CObject type_arguments_marker;
   Dart_CObject dynamic_type_marker;
 };
 
 
 class BaseWriter {
  public:
   // Size of the snapshot.
   intptr_t BytesWritten() const { return stream_.bytes_written(); }
@@ skipping 161 matching lines @@
 
  private:
   SnapshotWriter* writer_;
 
   DISALLOW_COPY_AND_ASSIGN(SnapshotWriterVisitor);
 };
 
 }  // namespace dart
 
 #endif  // VM_SNAPSHOT_H_