Re-enable MSVC warning 4800 for compiling with chromium_code

core/src/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp

Index: core/src/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp
diff --git a/core/src/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp b/core/src/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp
index feb152ba4a6db8c223a65b8d69751633f55b0865..30c494aca5b8409ca89d43f5ee4d8b3403818c0c 100644
--- a/core/src/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp
+++ b/core/src/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp
@@ -383,7 +383,7 @@ FX_BOOL CPDF_StandardSecurityHandler::AES256_CheckPassword(
   if (buf[9] != 'a' || buf[10] != 'd' || buf[11] != 'b') {
     return FALSE;
   }
-  if (FXDWORD_GET_LSBFIRST(buf) != m_Permissions) {
+  if (FXDWORD_GET_LSBFIRST(buf) != static_cast<int>(m_Permissions)) {

[Tom Sepez, 2016/03/11 00:30:28]

I'd really  like the return vale of FXDWORD_GET_LSBFIRST to be a FX_DWORD.  Its
macro is defined as 

#define FXDWORD_GET_LSBFIRST(p) \
  ((p[3] << 24) | (p[2] << 16) | (p[1] << 8) | (p[0]))

where p is expected to be an uint8_t, which when shifted gets promoted to int,
(not unsigned) because uint8_t fits in an int.

what we want is (((FX_DWORD)p[3]) << 24) | ... since left shifting a dword gets
promoted to unsigned int since dword doesn't fit in an int.

[Wei Li, 2016/03/11 04:11:36]

Done.

     return FALSE;
   }
   if ((buf[8] == 'T' && !IsMetadataEncrypted()) ||