Fix compilation failure due to overload of virtual function

test/unittests/value-serializer-unittest.cc

 // 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.
 
 #include "src/value-serializer.h"
 
 #include <algorithm>
 #include <string>
 
 #include "include/v8.h"
@@ skipping 1876 matching lines @@
 
 TEST_F(ValueSerializerTest, DecodeInvalidArrayBuffer) {
   InvalidDecodeTest({0xff, 0x09, 0x42, 0xff, 0xff, 0x00});
 }
 
 // An array buffer allocator that never has available memory.
 class OOMArrayBufferAllocator : public ArrayBuffer::Allocator {
  public:
   void* Allocate(size_t) override { return nullptr; }
   void* AllocateUninitialized(size_t) override { return nullptr; }
+  void* Reserve(size_t length) override { return nullptr; }
+  void Free(void* data, size_t length, AllocationMode mode) override {}
   void Free(void*, size_t) override {}
+  void SetProtection(void* data, size_t length,
+                     Protection protection) override {}
 };
 
 TEST_F(ValueSerializerTest, DecodeArrayBufferOOM) {
   // This test uses less of the harness, because it has to customize the
   // isolate.
   OOMArrayBufferAllocator allocator;
   Isolate::CreateParams params;
   params.array_buffer_allocator = &allocator;
   Isolate* isolate = Isolate::New(params);
   {
@@ skipping 1132 matching lines @@
   InvalidDecodeTest(raw);
 }
 
 TEST_F(ValueSerializerTestWithWasm, DecodeWasmModuleWithInvalidDataLength) {
   InvalidDecodeTest({0xff, 0x09, 0x3f, 0x00, 0x57, 0x79, 0x7f, 0x00});
   InvalidDecodeTest({0xff, 0x09, 0x3f, 0x00, 0x57, 0x79, 0x00, 0x7f});
 }
 
 }  // namespace
 }  // namespace v8