Reland "Use same blob format for internal and external snapshots."

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 f0cf1bb18f5c3d1cd8728e800da5ae4898cb069a..306813c01d3ef2cd14a53c30e6f158b9eb29f99c 100644
--- a/src/snapshot-source-sink.h
+++ b/src/snapshot-source-sink.h
@@ -19,8 +19,10 @@ namespace internal {
  */
 class SnapshotByteSource FINAL {
  public:
-  SnapshotByteSource(const byte* data, int length)
-      : data_(data), length_(length), position_(0) {}
+  SnapshotByteSource(const char* data, int length)
+      : data_(reinterpret_cast<const byte*>(data)),
+        length_(length),
+        position_(0) {}
 
   explicit SnapshotByteSource(Vector<const byte> payload)
       : data_(payload.start()), length_(payload.length()), position_(0) {}