ValueSerializer: Expose reading/writing doubles to embedder.

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 58 matching lines @@
   void TransferArrayBuffer(uint32_t transfer_id,
                            Handle<JSArrayBuffer> array_buffer);
 
   /*
    * Publicly exposed wire format writing methods.
    * These are intended for use within the delegate's WriteHostObject method.
    */
   void WriteUint32(uint32_t value);
   void WriteUint64(uint64_t value);
   void WriteRawBytes(const void* source, size_t length);
+  void WriteDouble(double value);
 
  private:
   // Writing the wire format.
   void WriteTag(SerializationTag tag);
   template <typename T>
   void WriteVarint(T value);
   template <typename T>
   void WriteZigZag(T value);
-  void WriteDouble(double value);
   void WriteOneByteString(Vector<const uint8_t> chars);
   void WriteTwoByteString(Vector<const uc16> chars);
   uint8_t* ReserveRawBytes(size_t bytes);
 
   // Writing V8 objects of various kinds.
   void WriteOddball(Oddball* oddball);
   void WriteSmi(Smi* smi);
   void WriteHeapNumber(HeapNumber* number);
   void WriteString(Handle<String> string);
   Maybe<bool> WriteJSReceiver(Handle<JSReceiver> receiver) WARN_UNUSED_RESULT;
@@ skipping 85 matching lines @@
    */
   void TransferArrayBuffer(uint32_t transfer_id,
                            Handle<JSArrayBuffer> array_buffer);
 
   /*
    * Publicly exposed wire format writing methods.
    * These are intended for use within the delegate's WriteHostObject method.
    */
   bool ReadUint32(uint32_t* value) WARN_UNUSED_RESULT;
   bool ReadUint64(uint64_t* value) WARN_UNUSED_RESULT;
+  bool ReadDouble(double* value) WARN_UNUSED_RESULT;
   bool ReadRawBytes(size_t length, const void** data) WARN_UNUSED_RESULT;
 
  private:
   // Reading the wire format.
   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>
@@ skipping 53 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_