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

Source/bindings/v8/V8ErrorHandler.cpp

 /*
  * Copyright (C) 2010 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 37 matching lines @@
     : V8EventListener(listener, isInline)
 {
 }
 
 v8::Local<v8::Value> V8ErrorHandler::callListenerFunction(ScriptExecutionContext* context, v8::Handle<v8::Value> jsEvent, Event* event)
 {
     if (!event->hasInterface(eventNames().interfaceForErrorEvent))
         return V8EventListener::callListenerFunction(context, jsEvent, event);
 
     ErrorEvent* errorEvent = static_cast<ErrorEvent*>(event);
+
+    v8::Isolate* isolate = toV8Context(context, world())->GetIsolate();
+    if (errorEvent->world() && errorEvent->world() != world())
+        return v8::Null(isolate);
+
     v8::Local<v8::Object> listener = getListenerObject(context);
-    v8::Isolate* isolate = toV8Context(context, world())->GetIsolate();
     v8::Local<v8::Value> returnValue;
     if (!listener.IsEmpty() && listener->IsFunction()) {
         v8::Local<v8::Function> callFunction = v8::Local<v8::Function>::Cast(listener);
         v8::Local<v8::Object> thisValue = v8::Context::GetCurrent()->Global();
 
         v8::Local<v8::Value> error = jsEvent->ToObject()->GetHiddenValue(V8HiddenPropertyName::error());
         if (error.IsEmpty())
             error = v8::Null(isolate);
 
         v8::Handle<v8::Value> parameters[5] = { v8String(errorEvent->message(), isolate), v8String(errorEvent->filename(), isolate), v8::Integer::New(errorEvent->lineno(), isolate), v8::Integer::New(errorEvent->colno(), isolate), error };
@@ skipping 16 matching lines @@
         v8::Local<v8::Object>::Cast(wrappedEvent)->SetHiddenValue(V8HiddenPropertyName::error(), data);
     }
 }
 
 bool V8ErrorHandler::shouldPreventDefault(v8::Local<v8::Value> returnValue)
 {
     return returnValue->IsBoolean() && returnValue->BooleanValue();
 }
 
 } // namespace WebCore