Trigger `window.onerror` only for exceptions thrown in the same world.

Source/core/dom/ErrorEvent.cpp

 /*
  * Copyright (C) 2009 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 36 matching lines @@
 {
     ScriptWrappable::init(this);
 }
 
 ErrorEvent::ErrorEvent(const AtomicString& type, const ErrorEventInit& initializer)
     : Event(type, initializer)
     , m_sanitizedMessage(initializer.message)
     , m_fileName(initializer.filename)
     , m_lineNumber(initializer.lineno)
     , m_columnNumber(initializer.colno)
+    , m_world(DOMWrapperWorld::current())
 {
     ScriptWrappable::init(this);
 }
 
-ErrorEvent::ErrorEvent(const String& message, const String& fileName, unsigned lineNumber, unsigned columnNumber)
+ErrorEvent::ErrorEvent(const String& message, const String& fileName, unsigned lineNumber, unsigned columnNumber, PassRefPtr<DOMWrapperWorld> world)
     : Event(eventNames().errorEvent, false, true)
     , m_sanitizedMessage(message)
     , m_fileName(fileName)
     , m_lineNumber(lineNumber)
     , m_columnNumber(columnNumber)
+    , m_world(world)
 {
     ScriptWrappable::init(this);
 }
 
 void ErrorEvent::setUnsanitizedMessage(const String& message)
 {
     ASSERT(m_unsanitizedMessage.isEmpty());
     m_unsanitizedMessage = message;
 }
 
 ErrorEvent::~ErrorEvent()
 {
 }
 
 const AtomicString& ErrorEvent::interfaceName() const
 {
     return eventNames().interfaceForErrorEvent;
 }
 
 } // namespace WebCore