More FWL interface cleanup.

xfa/fwl/core/fwl_threadimp.cpp

-// Copyright 2014 PDFium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
-
-#include "xfa/fwl/core/fwl_threadimp.h"
-
-#include "xfa/fwl/core/fwl_appimp.h"
-#include "xfa/fwl/core/fwl_noteimp.h"
-#include "xfa/fwl/core/fwl_targetimp.h"
-#include "xfa/fwl/core/ifwl_thread.h"
-
-void IFWL_Thread::Release() {
-  delete m_pImpl;
-}
-
-IFWL_NoteDriver* IFWL_Thread::GetNoteDriver() const {
-  return static_cast<CFWL_ThreadImp*>(GetImpl())->GetNoteDriver();
-}