Fix a bunch of -Wunused-but-set-variable warnings.

core/src/fxge/dib/fx_dib_transform.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_dib.h"
 #include "dib_int.h"
 int SDP_Table[513] = {
     256, 256, 256, 256, 256, 256, 256, 256, 256, 255, 255, 255, 255, 255, 255, 254, 254, 254, 254,
@@ skipping 52 matching lines @@
     if (dest_clip.IsEmpty()) {
         return NULL;
     }
     CFX_DIBitmap* pTransBitmap = new CFX_DIBitmap;
     int result_height = dest_clip.Height(), result_width = dest_clip.Width();
     if (!pTransBitmap->Create(result_width, result_height, GetFormat())) {
         delete pTransBitmap;
         return NULL;
     }
     pTransBitmap->CopyPalette(m_pPalette);
-    int src_pitch = m_Pitch;
     int dest_pitch = pTransBitmap->GetPitch();
     FX_LPBYTE dest_buf = pTransBitmap->GetBuffer();
     int row_start = bXFlip ? m_Height - dest_clip.right : dest_clip.left;
     int row_end = bXFlip ? m_Height - dest_clip.left : dest_clip.right;
     int col_start = bYFlip ? m_Width - dest_clip.bottom : dest_clip.top;
     int col_end = bYFlip ? m_Width - dest_clip.top : dest_clip.bottom;
     if (GetBPP() == 1) {
         FXSYS_memset8(dest_buf, 0xff, dest_pitch * result_height);
         for (int row = row_start; row < row_end; row ++) {
             FX_LPCBYTE src_scan = GetScanline(row);
@@ skipping 39 matching lines @@
                     for (int col = col_start; col < col_end; col ++) {
                         *dest_scan++ = *src_scan++;
                         *dest_scan++ = *src_scan++;
                         *dest_scan = *src_scan++;
                         dest_scan += dest_step;
                     }
             }
         }
     }
     if (m_pAlphaMask) {
-        src_pitch = m_pAlphaMask->m_Pitch;
         dest_pitch = pTransBitmap->m_pAlphaMask->GetPitch();
         dest_buf = pTransBitmap->m_pAlphaMask->GetBuffer();
         int dest_step = bYFlip ? -dest_pitch : dest_pitch;
         for (int row = row_start; row < row_end; row ++) {
             int dest_col = (bXFlip ? dest_clip.right - (row - row_start) - 1 : row) - dest_clip.left;
             FX_LPBYTE dest_scan = dest_buf + dest_col;
             if (bYFlip) {
                 dest_scan += (result_height - 1) * dest_pitch;
             }
             FX_LPCBYTE src_scan = m_pAlphaMask->GetScanline(row) + col_start;
@@ skipping 637 matching lines @@
                         }
                         dest_pos += destBpp;
                     }
                 }
             }
         }
     }
     m_Storer.Replace(pTransformed);
     return FALSE;
 }