Introduce code serializer/deserializer.

src/snapshot-source-sink.h

Index: src/snapshot-source-sink.h
diff --git a/src/snapshot-source-sink.h b/src/snapshot-source-sink.h
index 6e2328cc2774c59400c0c7e5ed98b228ba93e230..eae8606fbed11f31ff124b66518a9ff19d083292 100644
--- a/src/snapshot-source-sink.h
+++ b/src/snapshot-source-sink.h
@@ -82,6 +82,42 @@ class SnapshotByteSink {
 };
 
 
+class DummySnapshotSink : public SnapshotByteSink {
+ public:
+  DummySnapshotSink() : length_(0) {}
+  virtual ~DummySnapshotSink() {}
+  virtual void Put(int byte, const char* description) { length_++; }
+  virtual int Position() { return length_; }
+
+ private:
+  int length_;
+};
+
+
+// Wrap a SnapshotByteSink into a DebugSnapshotSink to get debugging output.
+class DebugSnapshotSink : public SnapshotByteSink {
+ public:
+  explicit DebugSnapshotSink(SnapshotByteSink* chained) : sink_(chained) {}
+  virtual void Put(int byte, const char* description) V8_OVERRIDE;
+  virtual int Position() V8_OVERRIDE { return sink_->Position(); }
+
+ private:
+  SnapshotByteSink* sink_;
+};
+
+
+class ListSnapshotSink : public i::SnapshotByteSink {
+ public:
+  explicit ListSnapshotSink(i::List<char>* data) : data_(data) {}
+  virtual void Put(int byte, const char* description) V8_OVERRIDE {
+    data_->Add(byte);
+  }
+  virtual int Position() V8_OVERRIDE { return data_->length(); }
+
+ private:
+  i::List<char>* data_;
+};
+
 }  // namespace v8::internal
 }  // namespace v8