Remove FX_DWORD from core/ and delete definition

core/fpdfapi/fpdf_render/include/cpdf_rendercontext.h

 // Copyright 2016 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_FPDFAPI_FPDF_RENDER_INCLUDE_CPDF_RENDERCONTEXT_H_
 #define CORE_FPDFAPI_FPDF_RENDER_INCLUDE_CPDF_RENDERCONTEXT_H_
 
 #include "core/fxcrt/include/fx_basic.h"
@@ skipping 32 matching lines @@
   void Render(CFX_RenderDevice* pDevice,
               const CPDF_PageObject* pStopObj,
               const CPDF_RenderOptions* pOptions,
               const CFX_Matrix* pFinalMatrix);
 
   void GetBackground(CFX_DIBitmap* pBuffer,
                      const CPDF_PageObject* pObj,
                      const CPDF_RenderOptions* pOptions,
                      CFX_Matrix* pFinalMatrix);
 
-  FX_DWORD CountLayers() const { return m_Layers.GetSize(); }
-  Layer* GetLayer(FX_DWORD index) { return m_Layers.GetDataPtr(index); }
+  uint32_t CountLayers() const { return m_Layers.GetSize(); }
+  Layer* GetLayer(uint32_t index) { return m_Layers.GetDataPtr(index); }
 
   CPDF_Document* GetDocument() const { return m_pDocument; }
   CPDF_Dictionary* GetPageResources() const { return m_pPageResources; }
   CPDF_PageRenderCache* GetPageCache() const { return m_pPageCache; }
 
  protected:
   CPDF_Document* const m_pDocument;
   CPDF_Dictionary* m_pPageResources;
   CPDF_PageRenderCache* m_pPageCache;
   FX_BOOL m_bFirstLayer;
   CFX_ArrayTemplate<Layer> m_Layers;
 };
 
 #endif  // CORE_FPDFAPI_FPDF_RENDER_INCLUDE_CPDF_RENDERCONTEXT_H_