bindings: Introduces ScriptWrappableBase to provide the internal pointer.

Source/bindings/core/v8/ScriptWrappable.cpp

Index: Source/bindings/core/v8/ScriptWrappable.cpp
diff --git a/Source/modules/crypto/AesKeyAlgorithm.h b/Source/bindings/core/v8/ScriptWrappable.cpp
similarity index 77%
copy from Source/modules/crypto/AesKeyAlgorithm.h
copy to Source/bindings/core/v8/ScriptWrappable.cpp
index 6194be77bf04b877286e441d2936c958467b9321..9c7ff976ae7cee2f59b85f3bb3ffa599f6ab7b56 100644
--- a/Source/modules/crypto/AesKeyAlgorithm.h
+++ b/Source/bindings/core/v8/ScriptWrappable.cpp
@@ -28,30 +28,20 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef AesKeyAlgorithm_h
-#define AesKeyAlgorithm_h
-
+#include "config.h"
 #include "bindings/core/v8/ScriptWrappable.h"
-#include "modules/crypto/KeyAlgorithm.h"
-#include "platform/heap/Handle.h"
-#include "wtf/Forward.h"
 
 namespace blink {
 
-class AesKeyAlgorithm : public KeyAlgorithm {
-public:
-    static AesKeyAlgorithm* create(const WebCryptoKeyAlgorithm&);
-
-    unsigned short length();
+struct SameSizeAsScriptWrappableBase { };
 
-    virtual void trace(Visitor*) OVERRIDE;
+COMPILE_ASSERT(sizeof(ScriptWrappableBase) <= sizeof(SameSizeAsScriptWrappableBase), ScriptWrappableBase_should_stay_small);
 
-private:
-    explicit AesKeyAlgorithm(const WebCryptoKeyAlgorithm&);
+struct SameSizeAsScriptWrappable : public ScriptWrappableBase {
+    virtual ~SameSizeAsScriptWrappable() { }
+    uintptr_t m_wrapperOrTypeInfo;
 };
 
-DEFINE_KEY_ALGORITHM_TYPE_CASTS(AesKeyAlgorithm);
+COMPILE_ASSERT(sizeof(ScriptWrappable) <= sizeof(SameSizeAsScriptWrappable), ScriptWrappable_should_stay_small);
 
 } // namespace blink
-
-#endif