Serializer: cache recent back references for shorter encoding.

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 68901a13190135a9cd457e968ec88f96285058e8..f701f54407493f695f1c6651469385a245dd63d0 100644
--- a/src/snapshot-source-sink.h
+++ b/src/snapshot-source-sink.h
@@ -24,7 +24,7 @@ class SnapshotByteSource FINAL {
 
   bool HasMore() { return position_ < length_; }
 
-  int Get() {
+  uint8_t Get() {

[mvstanton, 2014/12/03 08:22:41]

For simplicity, can the List<byte> below be a List<uint8_t>, or alternatively,
make Get() return byte.

[Yang, 2014/12/03 08:45:07]

Done.

     DCHECK(position_ < length_);
     return data_[position_++];
   }