Remove a few unused variables, functions, and tables.

core/src/fxge/dib/fx_dib_composite.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 "../../../include/fxge/fx_ge.h"
 #include "../../../include/fxcodec/fx_codec.h"
 #include "dib_int.h"
 const FX_BYTE g_GammaRamp[256] = {
@@ skipping 2933 matching lines @@
                           _BLEND(blend_type, back_color, *src_scan);
             dest_scan[index] = FX_GAMMA_INVERSE(FXDIB_ALPHA_MERGE(back_color, blended, src_alpha));
             src_scan ++;
         }
         dest_scan += dest_Bpp;
         src_scan ++;
     }
 }
 inline void _CompositeRow_Rgb2Argb_NoBlend_NoClip_RgbByteOrder(FX_LPBYTE dest_scan, FX_LPCBYTE src_scan, int width, int src_Bpp)
 {
-    int src_gap = src_Bpp - 3;
     for (int col = 0; col < width; col ++) {
         if (src_Bpp == 4) {
             FXARGB_SETRGBORDERDIB(dest_scan, 0xff000000 | FXARGB_GETDIB(src_scan));
         } else {
             FXARGB_SETRGBORDERDIB(dest_scan, FXARGB_MAKE(0xff, src_scan[2], src_scan[1], src_scan[0]));
         }
         dest_scan += 4;
         src_scan += src_Bpp;
     }
 }
@@ skipping 1628 matching lines @@
     }
     src_alpha_scan = m_pScanlineAlphaV;
     dest_alpha_scan = dest_alpha_buf;
     if (dest_alpha_scan) {
         for (i = 0; i < m_DestHeight; i ++) {
             *dest_alpha_scan = *src_alpha_scan++;
             dest_alpha_scan += y_alpha_step;
         }
     }
 }