Credential Manager: Add platform-exposed Credential objects.

Source/platform/credentialmanager/PlatformCredential.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/PlatformCredential.h"
+
+namespace blink {
+
+PlatformCredential* PlatformCredential::create(const String& id, const String& name, const String& avatarURL)
+{
+    return new PlatformCredential(id, name, avatarURL);
+}
+
+PlatformCredential::PlatformCredential(const String& id, const String& name, const String& avatarURL)
+    : m_id(id)
+    , m_name(name)
+    , m_avatarURL(avatarURL)
+{
+}
+
+PlatformCredential::~PlatformCredential()
+{
+}
+
+} // namespace blink