Follow object map transitions when deserializing object properties.

src/value-serializer.h

 // Copyright 2016 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_VALUE_SERIALIZER_H_
 #define V8_VALUE_SERIALIZER_H_
 
 #include <cstdint>
 #include <vector>
 
@@ skipping 169 matching lines @@
   Maybe<SerializationTag> PeekTag() const WARN_UNUSED_RESULT;
   void ConsumeTag(SerializationTag peeked_tag);
   Maybe<SerializationTag> ReadTag() WARN_UNUSED_RESULT;
   template <typename T>
   Maybe<T> ReadVarint() WARN_UNUSED_RESULT;
   template <typename T>
   Maybe<T> ReadZigZag() WARN_UNUSED_RESULT;
   Maybe<double> ReadDouble() WARN_UNUSED_RESULT;
   Maybe<Vector<const uint8_t>> ReadRawBytes(int size) WARN_UNUSED_RESULT;
 
+  // Reads a string if it matches the one provided.
+  // Returns true if this was the case. Otherwise, nothing is consumed.
+  bool ReadExpectedString(Handle<String> expected) WARN_UNUSED_RESULT;
+
   // Like ReadObject, but skips logic for special cases in simulating the
   // "stack machine".
   MaybeHandle<Object> ReadObjectInternal() WARN_UNUSED_RESULT;
 
   // Reading V8 objects of specific kinds.
   // The tag is assumed to have already been read.
   MaybeHandle<String> ReadUtf8String() WARN_UNUSED_RESULT;
   MaybeHandle<String> ReadTwoByteString() WARN_UNUSED_RESULT;
   MaybeHandle<JSObject> ReadJSObject() WARN_UNUSED_RESULT;
   MaybeHandle<JSArray> ReadSparseJSArray() WARN_UNUSED_RESULT;
   MaybeHandle<JSArray> ReadDenseJSArray() WARN_UNUSED_RESULT;
   MaybeHandle<JSDate> ReadJSDate() WARN_UNUSED_RESULT;
   MaybeHandle<JSValue> ReadJSValue(SerializationTag tag) WARN_UNUSED_RESULT;
   MaybeHandle<JSRegExp> ReadJSRegExp() WARN_UNUSED_RESULT;
   MaybeHandle<JSMap> ReadJSMap() WARN_UNUSED_RESULT;
   MaybeHandle<JSSet> ReadJSSet() WARN_UNUSED_RESULT;
   MaybeHandle<JSArrayBuffer> ReadJSArrayBuffer() WARN_UNUSED_RESULT;
   MaybeHandle<JSArrayBuffer> ReadTransferredJSArrayBuffer(bool is_shared)
       WARN_UNUSED_RESULT;
   MaybeHandle<JSArrayBufferView> ReadJSArrayBufferView(
       Handle<JSArrayBuffer> buffer) WARN_UNUSED_RESULT;
 
   /*
    * Reads key-value pairs into the object until the specified end tag is
    * encountered. If successful, returns the number of properties read.
    */
   Maybe<uint32_t> ReadJSObjectProperties(Handle<JSObject> object,
-                                         SerializationTag end_tag);
+                                         SerializationTag end_tag,
+                                         bool can_use_transitions);
 
   // Manipulating the map from IDs to reified objects.
   bool HasObjectWithID(uint32_t id);
   MaybeHandle<JSReceiver> GetObjectWithID(uint32_t id);
   void AddObjectWithID(uint32_t id, Handle<JSReceiver> object);
 
   Isolate* const isolate_;
   const uint8_t* position_;
   const uint8_t* const end_;
   uint32_t version_ = 0;
   uint32_t next_id_ = 0;
 
   // Always global handles.
   Handle<SeededNumberDictionary> id_map_;
   MaybeHandle<SeededNumberDictionary> array_buffer_transfer_map_;
 
   DISALLOW_COPY_AND_ASSIGN(ValueDeserializer);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_VALUE_SERIALIZER_H_