bindings: Adds DOMArrayBuffer, etc. as thin wrappers for ArrayBuffer, etc.

Source/core/dom/DOMArrayBufferView.h

+// Copyright 2014 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 DOMArrayBufferView_h
+#define DOMArrayBufferView_h
+
+#include "bindings/core/v8/ScriptWrappable.h"
+#include "core/dom/DOMArrayBuffer.h"
+#include "wtf/ArrayBufferView.h"
+#include "wtf/RefCounted.h"
+
+namespace blink {
+
+class DOMArrayBufferView : public RefCounted<DOMArrayBufferView>, public ScriptWrappable {
+    DEFINE_WRAPPERTYPEINFO();
+public:
+    PassRefPtr<DOMArrayBuffer> buffer() const
+    {
+        if (!m_domArrayBuffer)

[haraken, 2014/10/16 05:41:42]

Just to confirm: You want to create DOMArrayBuffer lazily, right?

[Yuki, 2014/10/16 14:21:51]

Yes.  IIUC, it's not often that we really need the wrapper to the underlying
ArrayBuffer.

+            m_domArrayBuffer = DOMArrayBuffer::create(view()->buffer());
+        return m_domArrayBuffer;
+    }
+
+    const WTF::ArrayBufferView* view() const { return m_bufferView.get(); }
+    WTF::ArrayBufferView* view() { return m_bufferView.get(); }
+
+    WTF::ArrayBufferView::ViewType type() const { return view()->type(); }
+    void* baseAddress() const { return view()->baseAddress(); }
+    unsigned long byteOffset() const { return view()->byteOffset(); }
+    unsigned long byteLength() const { return view()->byteLength(); }
+
+    virtual v8::Handle<v8::Object> wrap(v8::Handle<v8::Object> creationContext, v8::Isolate*) override
+    {
+        ASSERT_NOT_REACHED();
+        return v8::Handle<v8::Object>();
+    }
+    virtual v8::Handle<v8::Object> associateWithWrapper(const WrapperTypeInfo*, v8::Handle<v8::Object> wrapper, v8::Isolate*) override
+    {
+        ASSERT_NOT_REACHED();
+        return v8::Handle<v8::Object>();
+    }
+
+protected:
+    explicit DOMArrayBufferView(PassRefPtr<WTF::ArrayBufferView> bufferView)
+        : m_bufferView(bufferView)
+    {
+        ASSERT(m_bufferView);
+    }
+    DOMArrayBufferView(PassRefPtr<WTF::ArrayBufferView> bufferView, PassRefPtr<DOMArrayBuffer> domArrayBuffer)
+        : m_bufferView(bufferView), m_domArrayBuffer(domArrayBuffer)
+    {
+        ASSERT(m_bufferView);
+        ASSERT(m_domArrayBuffer);
+        ASSERT(m_domArrayBuffer->buffer() == m_bufferView->buffer());
+    }
+
+private:
+    RefPtr<WTF::ArrayBufferView> m_bufferView;
+    mutable RefPtr<DOMArrayBuffer> m_domArrayBuffer;
+};
+
+} // namespace blink
+
+#endif // DOMArrayBufferView_h