Serializer: cache recent back references for shorter encoding.

src/snapshot-source-sink.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_SNAPSHOT_SOURCE_SINK_H_
 #define V8_SNAPSHOT_SOURCE_SINK_H_
 
 #include "src/base/logging.h"
 #include "src/utils.h"
 
 namespace v8 {
 namespace internal {
 
 
 /**
  * Source to read snapshot and builtins files from.
  *
  * Note: Memory ownership remains with callee.
  */
 class SnapshotByteSource FINAL {
  public:
   SnapshotByteSource(const byte* array, int length);
   ~SnapshotByteSource();
 
   bool HasMore() { return position_ < length_; }
 
-  int Get() {
+  byte Get() {
     DCHECK(position_ < length_);
     return data_[position_++];
   }
 
   int32_t GetUnalignedInt();
 
   void Advance(int by) { position_ += by; }
 
   void CopyRaw(byte* to, int number_of_bytes);
 
@@ skipping 52 matching lines @@
   const List<byte>& data() const { return data_; }
 
  private:
   List<byte> data_;
 };
 
 }  // namespace v8::internal
 }  // namespace v8
 
 #endif  // V8_SNAPSHOT_SOURCE_SINK_H_