Simplify handling of Transferable objects while (de)serializing.

third_party/WebKit/Source/bindings/core/v8/Transferables.h

+// Copyright 2016 The Chromium 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 Transferables_h
+#define Transferables_h
+
+#include "core/CoreExport.h"
+#include "platform/heap/Handle.h"
+#include "wtf/Noncopyable.h"
+
+namespace blink {
+
+class DOMArrayBufferBase;
+class ImageBitmap;
+class MessagePort;
+
+using ArrayBufferArray = HeapVector<Member<DOMArrayBufferBase>>;
+using ImageBitmapArray = HeapVector<Member<ImageBitmap>>;
+using MessagePortArray = HeapVector<Member<MessagePort>>;
+
+class CORE_EXPORT Transferables final {

[xidachen, 2016/04/18 12:13:13]

Question:

With this class under core/ and marked as final, how would it work if I want to
make something under modules/ to be transferable?

[sof, 2016/04/18 18:28:01]

If you want to have such a thing, and it otherwise works out dependency-wise,
you can drop final and derive another STACK_ALLOCATED() transferable class. Or
just define the type in core/.

+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(Transferables);
+public:
+    Transferables()
+    {
+    }
+
+    ArrayBufferArray arrayBuffers;
+    ImageBitmapArray imageBitmaps;
+    MessagePortArray messagePorts;
+};
+
+// Along with extending |Transferables| to hold a new kind of transferable
+// objects, serialization handling code changes are required:
+//   - extend ScriptValueSerializer::copyTransferables()
+//   - alter SerializedScriptValue(Factory) to do the actual transfer.
+
+} // namespace blink
+
+#endif // Transferables_h