Do not allocate a buffer of 64KB by default when writing a message out. Start

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 94 matching lines @@
   ReAlloc alloc_;
   ApiGrowableArray<BackRefNode*> backward_references_;
 
   Dart_CObject type_arguments_marker;
   Dart_CObject dynamic_type_marker;
 };
 
 
 class ApiMessageWriter : public BaseWriter {
  public:
+  static const intptr_t kIncrementSize = 512;
   ApiMessageWriter(uint8_t** buffer, ReAlloc alloc)
-      : BaseWriter(buffer, alloc), object_id_(0),
+      : BaseWriter(buffer, alloc, kIncrementSize), object_id_(0),
         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);
 
@@ skipping 28 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_