Simplify handling of Transferable objects while (de)serializing.

third_party/WebKit/Source/bindings/core/v8/TransferableImageBitmap.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 TransferableImageBitmap_h
-#define TransferableImageBitmap_h
-
-#include "bindings/core/v8/Transferable.h"
-#include "core/CoreExport.h"
-#include "core/frame/ImageBitmap.h"
-
-namespace blink {
-
-class CORE_EXPORT TransferableImageBitmap : public Transferable {
-public:
-    ~TransferableImageBitmap() override { }
-    void append(ImageBitmap* imageBitmap)
-    {
-        m_imageBitmapArray.append(imageBitmap);
-    }
-    bool contains(ImageBitmap* imageBitmap)
-    {
-        return m_imageBitmapArray.contains(imageBitmap);
-    }
-    static TransferableImageBitmap* ensure(TransferableArray& transferables)
-    {
-        if (transferables.size() <= TransferableImageBitmapType) {
-            transferables.resize(TransferableImageBitmapType + 1);
-            transferables[TransferableImageBitmapType] = new TransferableImageBitmap();
-        }
-        return static_cast<TransferableImageBitmap*>(transferables[TransferableImageBitmapType].get());
-    }
-    static TransferableImageBitmap* get(TransferableArray& transferables)
-    {
-        if (transferables.size() <= TransferableImageBitmapType)
-            return nullptr;
-        return static_cast<TransferableImageBitmap*>(transferables[TransferableImageBitmapType].get());
-    }
-    HeapVector<Member<ImageBitmap>, 1>& getArray()
-    {
-        return m_imageBitmapArray;
-    }
-    DEFINE_INLINE_TRACE()
-    {
-        visitor->trace(m_imageBitmapArray);
-        Transferable::trace(visitor);
-    }
-private:
-    HeapVector<Member<ImageBitmap>, 1> m_imageBitmapArray;
-};
-
-} // namespace blink
-
-#endif // TransferableImageBitmap_h