Fix collison with Windows #define RGB macro.

core/include/fpdfdoc/fpdf_ap.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_INCLUDE_FPDFDOC_FPDF_AP_H_
 #define CORE_INCLUDE_FPDFDOC_FPDF_AP_H_
 
 #include "core/include/fpdfapi/fpdf_parser.h"
 #include "fpdf_vt.h"
 
 class IPVT_FontMap {
  public:
   virtual ~IPVT_FontMap() {}
   virtual CPDF_Font* GetPDFFont(int32_t nFontIndex) = 0;
   virtual CFX_ByteString GetPDFFontAlias(int32_t nFontIndex) = 0;
 };
 
 struct CPVT_Dash {
   CPVT_Dash(int32_t dash, int32_t gap, int32_t phase)
       : nDash(dash), nGap(gap), nPhase(phase) {}
 
   int32_t nDash;
   int32_t nGap;
   int32_t nPhase;
 };
 
 struct CPVT_Color {
-  enum Type { TRANSPARENT = 0, GRAY, RGB, CMYK };
+  enum Type { kTransparent = 0, kGray, kRGB, kCMYK };
 
-  CPVT_Color(Type type = TRANSPARENT,
+  CPVT_Color(Type type = kTransparent,
              FX_FLOAT color1 = 0.0f,
              FX_FLOAT color2 = 0.0f,
              FX_FLOAT color3 = 0.0f,
              FX_FLOAT color4 = 0.0f)
       : nColorType(type),
         fColor1(color1),
         fColor2(color2),
         fColor3(color3),
         fColor4(color4) {}
 
@@ skipping 49 matching lines @@
                                          const CPVT_Color& crLeftTop,
                                          const CPVT_Color& crRightBottom,
                                          int32_t nStyle,
                                          const CPVT_Dash& dash);
 
   static CFX_ByteString GenerateColorAP(const CPVT_Color& color,
                                         const FX_BOOL& bFillOrStroke);
 };
 
 #endif  // CORE_INCLUDE_FPDFDOC_FPDF_AP_H_