Support delegating serialization of host objects.

src/value-serializer.h

Index: src/value-serializer.h
diff --git a/src/value-serializer.h b/src/value-serializer.h
index 97dd0e8420b55d3cd33eed2908ddcd96300a1d2a..0879ddf72768af14ae35ee947bbdf36716b94223 100644
--- a/src/value-serializer.h
+++ b/src/value-serializer.h
@@ -69,6 +69,14 @@ class ValueSerializer {
   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);
+
  private:
   // Writing the wire format.
   void WriteTag(SerializationTag tag);
@@ -79,7 +87,6 @@ class ValueSerializer {
   void WriteDouble(double value);
   void WriteOneByteString(Vector<const uint8_t> chars);
   void WriteTwoByteString(Vector<const uc16> chars);
-  void WriteRawBytes(const void* source, size_t length);
   uint8_t* ReserveRawBytes(size_t bytes);
 
   // Writing V8 objects of various kinds.
@@ -98,6 +105,7 @@ class ValueSerializer {
   Maybe<bool> WriteJSSet(Handle<JSSet> map) WARN_UNUSED_RESULT;
   Maybe<bool> WriteJSArrayBuffer(JSArrayBuffer* array_buffer);
   Maybe<bool> WriteJSArrayBufferView(JSArrayBufferView* array_buffer);
+  Maybe<bool> WriteHostObject(Handle<JSObject> object) WARN_UNUSED_RESULT;
 
   /*
    * Reads the specified keys from the object and writes key-value pairs to the
@@ -138,7 +146,8 @@ class ValueSerializer {
  */
 class ValueDeserializer {
  public:
-  ValueDeserializer(Isolate* isolate, Vector<const uint8_t> data);
+  ValueDeserializer(Isolate* isolate, Vector<const uint8_t> data,
+                    v8::ValueDeserializer::Delegate* delegate);
   ~ValueDeserializer();
 
   /*
@@ -175,6 +184,14 @@ class ValueDeserializer {
   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 ReadRawBytes(size_t length, const void** data) WARN_UNUSED_RESULT;
+
  private:
   // Reading the wire format.
   Maybe<SerializationTag> PeekTag() const WARN_UNUSED_RESULT;
@@ -208,6 +225,7 @@ class ValueDeserializer {
       WARN_UNUSED_RESULT;
   MaybeHandle<JSArrayBufferView> ReadJSArrayBufferView(
       Handle<JSArrayBuffer> buffer) WARN_UNUSED_RESULT;
+  MaybeHandle<JSObject> ReadHostObject() WARN_UNUSED_RESULT;
 
   /*
    * Reads key-value pairs into the object until the specified end tag is
@@ -222,6 +240,7 @@ class ValueDeserializer {
   void AddObjectWithID(uint32_t id, Handle<JSReceiver> object);
 
   Isolate* const isolate_;
+  v8::ValueDeserializer::Delegate* const delegate_;
   const uint8_t* position_;
   const uint8_t* const end_;
   uint32_t version_ = 0;