Credential Manager: Add a 'formData' property to LocalCredential.

Source/modules/credentialmanager/LocalCredential.cpp

 // 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.
 
 #include "config.h"
 #include "modules/credentialmanager/LocalCredential.h"
 
 #include "bindings/core/v8/ExceptionState.h"
+#include "core/html/DOMFormData.h"
 #include "platform/credentialmanager/PlatformLocalCredential.h"
 #include "public/platform/WebCredential.h"
 #include "public/platform/WebLocalCredential.h"
 
 namespace blink {
 
 LocalCredential* LocalCredential::create(WebLocalCredential* webLocalCredential)
 {
     return new LocalCredential(webLocalCredential);
 }
 
 LocalCredential* LocalCredential::create(const String& id, const String& password, const String& name, const String& avatar, ExceptionState& exceptionState)
 {
     KURL avatarURL = parseStringAsURL(avatar, exceptionState);
     if (exceptionState.hadException())
         return nullptr;
     return new LocalCredential(id, password, name, avatarURL);
 }
 
 LocalCredential::LocalCredential(WebLocalCredential* webLocalCredential)
     : Credential(webLocalCredential->platformCredential())
 {
 }
 
 LocalCredential::LocalCredential(const String& id, const String& password, const String& name, const KURL& avatar)
     : Credential(PlatformLocalCredential::create(id, password, name, avatar))
+    , m_formData(DOMFormData::create())
 {
+    m_formData->append("username", id);
+    m_formData->append("password", password);
 }
 
 const String& LocalCredential::password() const
 {
     return static_cast<PlatformLocalCredential*>(m_platformCredential.get())->password();
 }
 
+void LocalCredential::trace(Visitor* visitor)
+{
+    visitor->trace(m_formData);
+    Credential::trace(visitor);
+}
+
 } // namespace blink