ValueSerializer: Share string encoding code with String and RegExp objects.

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 211 matching lines @@
   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;
 
+  // Reads a string intended to be part of a more complicated object.
+  // Before v12, these are UTF-8 strings. After, they can be any encoding
+  // permissible for a string (with the relevant tag).
+  MaybeHandle<String> ReadString() 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> ReadOneByteString() 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;
@@ skipping 33 matching lines @@
   Handle<FixedArray> id_map_;
   MaybeHandle<SeededNumberDictionary> array_buffer_transfer_map_;
 
   DISALLOW_COPY_AND_ASSIGN(ValueDeserializer);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_VALUE_SERIALIZER_H_