CREDENTIAL: Add 'PasswordCredential::toFormData()'

Source/modules/credentialmanager/PasswordCredential.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PasswordCredential_h
 #define PasswordCredential_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "bindings/core/v8/SerializedScriptValue.h"
 #include "modules/credentialmanager/Credential.h"
 #include "platform/heap/Handle.h"
 #include "platform/weborigin/KURL.h"
 
 namespace blink {
 
 class DOMFormData;
+class FormDataOptions;
 class WebPasswordCredential;
 
 class PasswordCredential final : public Credential {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PasswordCredential* create(const String& id, const String& password, ExceptionState& exceptionState)
     {
         return create(id, password, emptyString(), emptyString(), exceptionState);
     }
 
     static PasswordCredential* create(const String& id, const String& password, const String& name, ExceptionState& exceptionState)
     {
         return create(id, password, name, emptyString(), exceptionState);
     }
 
     static PasswordCredential* create(const String& id, const String& password, const String& name, const String& icon, ExceptionState&);
     static PasswordCredential* create(WebPasswordCredential*);
 
     // PasswordCredential.idl
-    const String& password() const;
-    DOMFormData* formData() const { return m_formData; }
+    DOMFormData* toFormData(ScriptState*, const FormDataOptions&);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     PasswordCredential(WebPasswordCredential*);
     PasswordCredential(const String& id, const String& password, const String& name, const KURL& icon);
 
-    Member<DOMFormData> m_formData;
+    const String& password() const;
 };
 
 } // namespace blink
 
 #endif // PasswordCredential_h