Re-enable several MSVC warnings

core/fxge/dib/fx_dib_main.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 "core/include/fxge/fx_dib.h"
 
 #include <limits.h>
 
@@ skipping 1216 matching lines @@
           bFlipX ? (m_Width - dest_x * m_Width / dest_width - 1) * src_Bpp
                  : (dest_x * m_Width / dest_width) * src_Bpp;
       src_x %= m_Width * src_Bpp;
       int dest_pos = i * src_Bpp;
       for (int b = 0; b < src_Bpp; b++) {
         dest_scan[dest_pos + b] = scanline[src_x + b];
       }
     }
   }
 }
+
+// TODO(weili): Split this function into two for handling CMYK and RGB
+// colors separately.
 FX_BOOL CFX_DIBitmap::ConvertColorScale(FX_DWORD forecolor,
                                         FX_DWORD backcolor) {
   ASSERT(!IsAlphaMask());
   if (!m_pBuffer || IsAlphaMask()) {
     return FALSE;
   }
-  int fc, fm, fy, fk, bc, bm, by, bk;
-  int fr, fg, fb, br, bg, bb;
+  // Values used for CMYK colors.
+  int fc = 0;
+  int fm = 0;
+  int fy = 0;
+  int fk = 0;
+  int bc = 0;
+  int bm = 0;
+  int by = 0;
+  int bk = 0;
+  // Values used for RGB colors.
+  int fr = 0;
+  int fg = 0;
+  int fb = 0;
+  int br = 0;
+  int bg = 0;
+  int bb = 0;
   FX_BOOL isCmykImage = IsCmykImage();
   if (isCmykImage) {
     fc = FXSYS_GetCValue(forecolor);
     fm = FXSYS_GetMValue(forecolor);
     fy = FXSYS_GetYValue(forecolor);
     fk = FXSYS_GetKValue(forecolor);
     bc = FXSYS_GetCValue(backcolor);
     bm = FXSYS_GetMValue(backcolor);
     by = FXSYS_GetYValue(backcolor);
     bk = FXSYS_GetKValue(backcolor);
@@ skipping 481 matching lines @@
   if (!m_pBitmap->Create(width, height, src_format)) {
     delete m_pBitmap;
     m_pBitmap = NULL;
     return FALSE;
   }
   if (pSrcPalette) {
     m_pBitmap->CopyPalette(pSrcPalette);
   }
   return TRUE;
 }