allow disabling of ArrayBuffer neutering

src/api.cc

 // Copyright 2012 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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 6020 matching lines @@
   i::Handle<i::Symbol> key = isolate->factory()->promise_has_handler_symbol();
   return i::JSObject::GetDataProperty(promise, key)->IsTrue();
 }
 
 
 bool v8::ArrayBuffer::IsExternal() const {
   return Utils::OpenHandle(this)->is_external();
 }
 
 
+bool v8::ArrayBuffer::IsNeuterable() const {
+  return Utils::OpenHandle(this)->is_neuterable();
+}
+
+
 v8::ArrayBuffer::Contents v8::ArrayBuffer::Externalize() {
   i::Handle<i::JSArrayBuffer> obj = Utils::OpenHandle(this);
   Utils::ApiCheck(!obj->is_external(),
                   "v8::ArrayBuffer::Externalize",
                   "ArrayBuffer already externalized");
   obj->set_is_external(true);
   size_t byte_length = static_cast<size_t>(obj->byte_length()->Number());
   Contents contents;
   contents.data_ = obj->backing_store();
   contents.byte_length_ = byte_length;
   return contents;
 }
 
 
 void v8::ArrayBuffer::Neuter() {
   i::Handle<i::JSArrayBuffer> obj = Utils::OpenHandle(this);
   i::Isolate* isolate = obj->GetIsolate();
   Utils::ApiCheck(obj->is_external(),
                   "v8::ArrayBuffer::Neuter",
                   "Only externalized ArrayBuffers can be neutered");
+  Utils::ApiCheck(obj->is_neuterable(), "v8::ArrayBuffer::Neuter",
+                  "Only neuterable ArrayBuffers can be neutered");
   LOG_API(obj->GetIsolate(), "v8::ArrayBuffer::Neuter()");
   ENTER_V8(isolate);
   i::Runtime::NeuterArrayBuffer(obj);
 }
 
 
 size_t v8::ArrayBuffer::ByteLength() const {
   i::Handle<i::JSArrayBuffer> obj = Utils::OpenHandle(this);
   return static_cast<size_t>(obj->byte_length()->Number());
 }
@@ skipping 1660 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal