Fix more disabled MSVC warnings, base/ edition.

base/json/json_parser.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/json/json_parser.h"
 
 #include "base/float_util.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 634 matching lines @@
           }
 
           int hex_digit = 0;
           if (!HexStringToInt(StringPiece(NextChar(), 2), &hex_digit)) {
             ReportError(JSONReader::JSON_INVALID_ESCAPE, -1);
             return false;
           }
           NextChar();
 
           if (hex_digit < kExtendedASCIIStart)
-            string.Append(hex_digit);
+            string.Append(static_cast<char>(hex_digit));
           else
             DecodeUTF8(hex_digit, &string);
           break;
         }
         case 'u': {  // UTF-16 sequence.
           // UTF units are of the form \uXXXX.
           if (!CanConsume(5)) {  // 5 being 'u' and four HEX digits.
             ReportError(JSONReader::JSON_INVALID_ESCAPE, 0);
             return false;
           }
@@ skipping 41 matching lines @@
         default:
           ReportError(JSONReader::JSON_INVALID_ESCAPE, 0);
           return false;
       }
     } else if (next_char == '"') {
       --index_;  // Rewind by one because of CBU8_NEXT.
       out->Swap(&string);
       return true;
     } else {
       if (next_char < kExtendedASCIIStart)
-        string.Append(next_char);
+        string.Append(static_cast<char>(next_char));
       else
         DecodeUTF8(next_char, &string);
     }
   }
 
   ReportError(JSONReader::JSON_SYNTAX_ERROR, 0);
   return false;
 }
 
 // Entry is at the first X in \uXXXX.
@@ skipping 56 matching lines @@
   }
 
   dest_string->append(code_unit8);
   return true;
 }
 
 void JSONParser::DecodeUTF8(const int32& point, StringBuilder* dest) {
   // Anything outside of the basic ASCII plane will need to be decoded from
   // int32 to a multi-byte sequence.
   if (point < kExtendedASCIIStart) {
-    dest->Append(point);
+    dest->Append(static_cast<char>(point));
   } else {
     char utf8_units[4] = { 0 };
     int offset = 0;
     CBU8_APPEND_UNSAFE(utf8_units, offset, point);
     dest->Convert();
     // CBU8_APPEND_UNSAFE can overwrite up to 4 bytes, so utf8_units may not be
     // zero terminated at this point.  |offset| contains the correct length.
     dest->AppendString(std::string(utf8_units, offset));
   }
 }
@@ skipping 151 matching lines @@
                                            const std::string& description) {
   if (line || column) {
     return StringPrintf("Line: %i, column: %i, %s",
         line, column, description.c_str());
   }
   return description;
 }
 
 }  // namespace internal
 }  // namespace base