bindings: Introduces type-check for the internal pointers.

Source/bindings/core/v8/NPV8Object.cpp

 /*
  * Copyright (C) 2004, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2007, 2008, 2009 Google, Inc.  All rights reserved.
  * Copyright (C) 2014 Opera Software ASA. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 94 matching lines @@
     if (identifier->isString)
         return v8AtomicString(isolate, static_cast<const char*>(identifier->value.string));
 
     char buffer[32];
     snprintf(buffer, sizeof(buffer), "%d", identifier->value.number);
     return v8AtomicString(isolate, buffer);
 }
 
 NPObject* v8ObjectToNPObject(v8::Handle<v8::Object> object)
 {
-    return reinterpret_cast<NPObject*>(object->GetAlignedPointerFromInternalField(v8DOMWrapperObjectIndex));
+    return reinterpret_cast<NPObject*>(toInternalPointer(object));
 }
 
 bool isWrappedNPObject(v8::Handle<v8::Object> object)
 {
     if (object->InternalFieldCount() == npObjectInternalFieldCount) {
         const WrapperTypeInfo* typeInfo = static_cast<const WrapperTypeInfo*>(object->GetAlignedPointerFromInternalField(v8DOMWrapperTypeIndex));
         return typeInfo == npObjectTypeInfo();
     }
     return false;
 }
@@ skipping 44 matching lines @@
 V8NPObject* npObjectToV8NPObject(NPObject* npObject)
 {
     if (npObject->_class != &V8NPObjectClass)
         return 0;
     V8NPObject* v8NpObject = reinterpret_cast<V8NPObject*>(npObject);
     if (v8NpObject->v8Object.IsEmpty())
         return 0;
     return v8NpObject;
 }
 
+ScriptWrappableBase* npObjectToInternalPointer(NPObject* npObject)
+{
+    return reinterpret_cast<ScriptWrappableBase*>(npObject);
+}
+
 void disposeUnderlyingV8Object(NPObject* npObject, v8::Isolate* isolate)
 {
     ASSERT(npObject);
     V8NPObject* v8NpObject = npObjectToV8NPObject(npObject);
     if (!v8NpObject)
         return;
     v8::HandleScope scope(isolate);
     v8::Handle<v8::Object> v8Object = v8::Local<v8::Object>::New(isolate, v8NpObject->v8Object);
     ASSERT(!v8Object->CreationContext().IsEmpty());
     if (V8PerContextData* perContextData = V8PerContextData::from(v8Object->CreationContext())) {
@@ skipping 417 matching lines @@
 
         convertV8ObjectToNPVariant(resultObject, npObject, result, isolate);
         return true;
     }
 
     if (NP_CLASS_STRUCT_VERSION_HAS_CTOR(npObject->_class) && npObject->_class->construct)
         return npObject->_class->construct(npObject, arguments, argumentCount, result);
 
     return false;
 }