Re-enable several MSVC warnings

fpdfsdk/fpdfview.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 "public/fpdfview.h"
 
 #include <memory>
 
@@ skipping 264 matching lines @@
 void SetLastError(int err) {
   g_LastError = err;
 }
 
 int GetLastError() {
   return g_LastError;
 }
 #endif  // _WIN32
 
 void ProcessParseError(CPDF_Parser::Error err) {
-  FX_DWORD err_code;
+  FX_DWORD err_code = FPDF_ERR_SUCCESS;
   // Translate FPDFAPI error code to FPDFVIEW error code
   switch (err) {
     case CPDF_Parser::SUCCESS:
       err_code = FPDF_ERR_SUCCESS;
       break;
     case CPDF_Parser::FILE_ERROR:
       err_code = FPDF_ERR_FILE;
       break;
     case CPDF_Parser::FORMAT_ERROR:
       err_code = FPDF_ERR_FORMAT;
@@ skipping 862 matching lines @@
   if (!buffer) {
     *buflen = len;
   } else if (*buflen >= len) {
     memcpy(buffer, utf16Name.c_str(), len);
     *buflen = len;
   } else {
     *buflen = -1;
   }
   return (FPDF_DEST)pDestObj;
 }