Credential Management: Add 'Credential::type' attribute.

Source/platform/credentialmanager/PlatformLocalCredential.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 "platform/credentialmanager/PlatformLocalCredential.h"
 
 namespace blink {
 
 PlatformLocalCredential* PlatformLocalCredential::create(const String& id, const String& password, const String& name, const KURL& avatarURL)
 {
     return new PlatformLocalCredential(id, password, name, avatarURL);
 }
 
 PlatformLocalCredential::PlatformLocalCredential(const String& id, const String& password, const String& name, const KURL& avatarURL)
     : PlatformCredential(id, name, avatarURL)
     , m_password(password)
 {
+    setType("password");
 }
 
 PlatformLocalCredential::~PlatformLocalCredential()
 {
 }
 
 } // namespace blink