Re-enable MSVC warning 4800 for compiling with chromium_code

core/include/fxcrt/fx_ext.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_FXCRT_FX_EXT_H_
 #define CORE_INCLUDE_FXCRT_FX_EXT_H_
 
 #include <cctype>
@@ skipping 42 matching lines @@
 }
 
 inline int FXSYS_toHexDigit(const FX_CHAR c) {
   if (!std::isxdigit(c))
     return 0;
   char upchar = std::toupper(c);
   return upchar > '9' ? upchar - 'A' + 10 : upchar - '0';
 }
 
 inline bool FXSYS_isDecimalDigit(const FX_CHAR c) {
-  return std::isdigit(c);
+  return !!std::isdigit(c);
 }
 
 inline bool FXSYS_isDecimalDigit(const FX_WCHAR c) {
-  return std::iswdigit(c);
+  return !!std::iswdigit(c);
 }
 
 inline int FXSYS_toDecimalDigit(const FX_CHAR c) {
-  if (!std::isdigit(c))
-    return 0;
-  return c - '0';
+  return std::isdigit(c) ? c - '0' : 0;
 }
 
 inline int FXSYS_toDecimalDigit(const FX_WCHAR c) {
-  if (!std::iswdigit(c))
-    return 0;
-  return c - L'0';
+  return std::iswdigit(c) ? c - L'0' : 0;
 }
 
 FX_DWORD FX_HashCode_String_GetA(const FX_CHAR* pStr,
                                  int32_t iLength,
                                  FX_BOOL bIgnoreCase = FALSE);
 FX_DWORD FX_HashCode_String_GetW(const FX_WCHAR* pStr,
                                  int32_t iLength,
                                  FX_BOOL bIgnoreCase = FALSE);
 
 void* FX_Random_MT_Start(FX_DWORD dwSeed);
@@ skipping 39 matching lines @@
           j -= gap;
         }
         pArray[j + gap] = v1;
       }
       gap >>= 1;
     }
   }
 };
 
 #endif  // CORE_INCLUDE_FXCRT_FX_EXT_H_