Avoid trusting the length encoded in the Snapshot if there is an

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"
 
@@ skipping 106 matching lines @@
         forward_list_(NULL), forward_list_length_(0), forward_id_(0) {
     ASSERT(kDartCObjectTypeMask >= Dart_CObject::kNumberOfTypes - 1);
   }
   ~ApiMessageWriter() {
     ::free(forward_list_);
   }
 
   // Writes a message of integers.
   void WriteMessage(intptr_t field_count, intptr_t *data);
 
+  // Writes a message with a single object.
   void WriteCMessage(Dart_CObject* object);
 
-  void FinalizeBuffer() {
-    BaseWriter::FinalizeBuffer(Snapshot::kMessage);
-  }
-
  private:
   static const intptr_t kDartCObjectTypeBits = 4;
   static const intptr_t kDartCObjectTypeMask = (1 << kDartCObjectTypeBits) - 1;
   static const intptr_t kDartCObjectMarkMask = ~kDartCObjectTypeMask;
   static const intptr_t kDartCObjectMarkOffset = 1;
 
   void MarkCObject(Dart_CObject* object, intptr_t object_id);
   void UnmarkCObject(Dart_CObject* object);
   bool IsCObjectMarked(Dart_CObject* object);
   intptr_t GetMarkedCObjectMark(Dart_CObject* object);
@@ skipping 15 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_