Encode reservation meta data in the snapshot blob.

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 398276fe5fda31f0c81d46d34a4fd1f60982f42b..f0cf1bb18f5c3d1cd8728e800da5ae4898cb069a 100644
--- a/src/snapshot-source-sink.h
+++ b/src/snapshot-source-sink.h
@@ -19,8 +19,13 @@ namespace internal {
  */
 class SnapshotByteSource FINAL {
  public:
-  SnapshotByteSource(const byte* array, int length);
-  ~SnapshotByteSource();
+  SnapshotByteSource(const byte* data, int length)
+      : data_(data), length_(length), position_(0) {}
+
+  explicit SnapshotByteSource(Vector<const byte> payload)
+      : data_(payload.start()), length_(payload.length()), position_(0) {}
+
+  ~SnapshotByteSource() {}
 
   bool HasMore() { return position_ < length_; }
 
@@ -83,8 +88,8 @@ class SnapshotByteSink {
   }
 
   void PutInt(uintptr_t integer, const char* description);
-  void PutRaw(byte* data, int number_of_bytes, const char* description);
-  void PutBlob(byte* data, int number_of_bytes, const char* description);
+  void PutRaw(const byte* data, int number_of_bytes, const char* description);
+  void PutBlob(Vector<const byte> blob, const char* description);
   int Position() { return data_.length(); }
 
   const List<byte>& data() const { return data_; }