submit() in submit event handler should not contains a value of a submit button.

third_party/WebKit/Source/core/loader/FormSubmission.h

 /*
  * 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 24 matching lines @@
 #include "platform/heap/Handle.h"
 #include "platform/weborigin/KURL.h"
 #include "platform/weborigin/Referrer.h"
 #include "wtf/Allocator.h"
 
 namespace blink {
 
 class Document;
 class EncodedFormData;
 class Event;
+class HTMLFormControlElement;
 class HTMLFormElement;
 
 class FormSubmission : public GarbageCollectedFinalized<FormSubmission> {
 public:
     enum SubmitMethod { GetMethod, PostMethod, DialogMethod };
 
     class Attributes {
         DISALLOW_NEW();
         WTF_MAKE_NONCOPYABLE(Attributes);
     public:
@@ skipping 28 matching lines @@
     private:
         SubmitMethod m_method;
         bool m_isMultiPartForm;
 
         String m_action;
         AtomicString m_target;
         AtomicString m_encodingType;
         String m_acceptCharset;
     };
 
-    static FormSubmission* create(HTMLFormElement*, const Attributes&, Event*);
+    static FormSubmission* create(HTMLFormElement*, const Attributes&, Event*, HTMLFormControlElement* submitButton);
     DECLARE_TRACE();
 
     FrameLoadRequest createFrameLoadRequest(Document* originDocument);
 
     KURL requestURL() const;
 
     SubmitMethod method() const { return m_method; }
     const KURL& action() const { return m_action; }
     const AtomicString& target() const { return m_target; }
     void clearTarget() { m_target = nullAtom; }
@@ skipping 15 matching lines @@
     Member<HTMLFormElement> m_form;
     RefPtr<EncodedFormData> m_formData;
     String m_boundary;
     Member<Event> m_event;
     String m_result;
 };
 
 } // namespace blink
 
 #endif // FormSubmission_h