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

Source/core/dom/ErrorEvent.h

 /*
  * 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 18 matching lines @@
  */
 
 #ifndef ErrorEvent_h
 #define ErrorEvent_h
 
 #include "core/dom/Event.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
+class DOMWrapperWorld;
+
 struct ErrorEventInit : public EventInit {
     ErrorEventInit();
 
     String message;
     String filename;
     unsigned lineno;
     unsigned colno;
 };
 
 class ErrorEvent : public Event {
 public:
     static PassRefPtr<ErrorEvent> create()
     {
         return adoptRef(new ErrorEvent);
     }
-    static PassRefPtr<ErrorEvent> create(const String& message, const String& fileName, unsigned lineNumber, unsigned columnNumber)
+    static PassRefPtr<ErrorEvent> create(const String& message, const String& fileName, unsigned lineNumber, unsigned columnNumber, DOMWrapperWorld* world)
     {
-        return adoptRef(new ErrorEvent(message, fileName, lineNumber, columnNumber));
+        return adoptRef(new ErrorEvent(message, fileName, lineNumber, columnNumber, world));
     }
     static PassRefPtr<ErrorEvent> create(const AtomicString& type, const ErrorEventInit& initializer)
     {
         return adoptRef(new ErrorEvent(type, initializer));
     }
     static PassRefPtr<ErrorEvent> createSanitizedError()

[adamk, 2013/09/05 19:24:20]

What is this used for? Why is passing 0 for world always correct?

[Mike West, 2013/09/06 11:57:03]

This is used for cross-origin onerror messages: they are sanitized to prevent
information leakage about the state of cross-origin script.

I don't think there's any case where we'd sanitize an extension's script, since
it's injected into the page directly. That said, you're probably right to say
that we should covering the edge-case explicitly by adding a world parameter.
I'll do that.

     {
-        return adoptRef(new ErrorEvent("Script error.", String(), 0, 0));
+        return adoptRef(new ErrorEvent("Script error.", String(), 0, 0, 0));
     }
     virtual ~ErrorEvent();
 
     // As 'message' is exposed to JavaScript, never return unsanitizedMessage.
     const String& message() const { return m_sanitizedMessage; }
     const String& filename() const { return m_fileName; }
     unsigned lineno() const { return m_lineNumber; }
     unsigned colno() const { return m_columnNumber; }
 
     // 'messageForConsole' is not exposed to JavaScript, and prefers 'm_unsanitizedMessage'.
     const String& messageForConsole() const { return !m_unsanitizedMessage.isEmpty() ? m_unsanitizedMessage : m_sanitizedMessage; }
 
     virtual const AtomicString& interfaceName() const;
 
+    DOMWrapperWorld* world() const { return m_world; }
+
     void setUnsanitizedMessage(const String&);
 
 private:
     ErrorEvent();
-    ErrorEvent(const String& message, const String& fileName, unsigned lineNumber, unsigned columnNumber);
+    ErrorEvent(const String& message, const String& fileName, unsigned lineNumber, unsigned columnNumber, DOMWrapperWorld*);
     ErrorEvent(const AtomicString&, const ErrorEventInit&);
 
     String m_unsanitizedMessage;
     String m_sanitizedMessage;
     String m_fileName;
     unsigned m_lineNumber;
     unsigned m_columnNumber;
+
+    DOMWrapperWorld* m_world;

[adamk, 2013/09/05 19:24:20]

Seems a little bit scary to skip a RefPtr here. As you're currently using it,
only the object identity is important, but is there any downside to holding a
Ref?

[Mike West, 2013/09/06 11:57:03]

No good reason, as long as there aren't any side-effects I can't think of to
holding a reference. I'll change the implementation.

 };
 
 } // namespace WebCore
 
 #endif // ErrorEvent_h