Reland "Remove the weak list of array buffers"

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 6236 matching lines @@
 }
 
 
 bool v8::ArrayBuffer::IsNeuterable() const {
   return Utils::OpenHandle(this)->is_neuterable();
 }
 
 
 v8::ArrayBuffer::Contents v8::ArrayBuffer::Externalize() {
   i::Handle<i::JSArrayBuffer> self = Utils::OpenHandle(this);
+  i::Isolate* isolate = self->GetIsolate();
   Utils::ApiCheck(!self->is_external(), "v8::ArrayBuffer::Externalize",
                   "ArrayBuffer already externalized");
   self->set_is_external(true);
+  isolate->heap()->UnregisterArrayBuffer(self->backing_store());
+
   return GetContents();
 }
 
 
 v8::ArrayBuffer::Contents v8::ArrayBuffer::GetContents() {
   i::Handle<i::JSArrayBuffer> self = Utils::OpenHandle(this);
   size_t byte_length = static_cast<size_t>(self->byte_length()->Number());
   Contents contents;
   contents.data_ = self->backing_store();
   contents.byte_length_ = byte_length;
@@ skipping 1770 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