V8 Binding: Introduce toNativeWithTypeCheck

Source/bindings/v8/custom/V8InjectedScriptHostCustom.cpp

 /*
  * Copyright (C) 2007-2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 261 matching lines @@
         result->Set(v8::Number::New(isolate, outputIndex++), listenerEntry);
     }
     return result;
 }
 
 void V8InjectedScriptHost::getEventListenersMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     if (info.Length() < 1)
         return;
 
-    EventTarget* target = 0;
+
     v8::Local<v8::Value> value = info[0];
-
-    if (V8EventTarget::hasInstance(value, info.GetIsolate()))
-        target = V8EventTarget::toNative(value->ToObject());
+    EventTarget* target = V8EventTarget::toNativeWithTypeCheck(info.GetIsolate(), value);
 
     // We need to handle a DOMWindow specially, because a DOMWindow wrapper exists on a prototype chain.
     if (!target)
         target = toDOMWindow(value, info.GetIsolate());
 
     if (!target || !target->executionContext())
         return;
 
     InjectedScriptHost* host = V8InjectedScriptHost::toNative(info.Holder());
     Vector<EventListenerInfo> listenersArray;
@@ skipping 124 matching lines @@
     int lineNumber;
     int columnNumber;
     if (!getFunctionLocation(info, &scriptId, &lineNumber, &columnNumber))
         return;
 
     InjectedScriptHost* host = V8InjectedScriptHost::toNative(info.Holder());
     host->unmonitorFunction(scriptId, lineNumber, columnNumber);
 }
 
 } // namespace WebCore