Refactor fxge/fx_apple and fx_win header files

core/fxge/include/fx_ge_apple.h

-// 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
-
-#ifndef CORE_FXGE_INCLUDE_FX_GE_APPLE_H_
-#define CORE_FXGE_INCLUDE_FX_GE_APPLE_H_
-
-#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
-
-#include "core/fxge/include/fx_ge.h"
-
-class CFX_QuartzDevice : public CFX_RenderDevice {
- public:
-  CFX_QuartzDevice();
-  ~CFX_QuartzDevice() override;
-
-  FX_BOOL Attach(CGContextRef context, int32_t nDeviceClass = FXDC_DISPLAY);
-  FX_BOOL Attach(CFX_DIBitmap* pBitmap);
-  FX_BOOL Create(int32_t width, int32_t height, FXDIB_Format format);
-
-  CGContextRef GetContext();
-
- protected:
-  CGContextRef m_pContext;
-  FX_BOOL m_bOwnedBitmap;
-};
-#endif
-
-#endif  // CORE_FXGE_INCLUDE_FX_GE_APPLE_H_