Added API Dart_PostCMessage for posting a Dart_CMessage structure

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 517 matching lines @@
 
  private:
   WriteStream stream_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(BaseWriter);
 };
 
 
 class MessageWriter : public BaseWriter {
  public:
-  MessageWriter(uint8_t** buffer, ReAlloc alloc) : BaseWriter(buffer, alloc) {
+  MessageWriter(uint8_t** buffer, ReAlloc alloc) : BaseWriter(buffer, alloc),
+                                                   object_id_(0) {
   }
   ~MessageWriter() { }
 
   // Writes a message of integers.
   void WriteMessage(intptr_t field_count, intptr_t *data);
 
+  void WriteCMessage(Dart_CObject* object);
+
   void FinalizeBuffer() {
     BaseWriter::FinalizeBuffer(Snapshot::kMessage);
   }
 
  private:
+  void WriteSmi(int32_t value);
+  void WriteCObject(Dart_CObject* object);
+
+  intptr_t object_id_;
+
   DISALLOW_COPY_AND_ASSIGN(MessageWriter);
 };
 
 
 class SnapshotWriter : public BaseWriter {
  public:
   SnapshotWriter(Snapshot::Kind kind, uint8_t** buffer, ReAlloc alloc)
       : BaseWriter(buffer, alloc),
         kind_(kind),
         object_store_(Isolate::Current()->object_store()),
@@ skipping 78 matching lines @@
 
  private:
   SnapshotWriter* writer_;
 
   DISALLOW_COPY_AND_ASSIGN(SnapshotWriterVisitor);
 };
 
 }  // namespace dart
 
 #endif  // VM_SNAPSHOT_H_