Fix tautologous DCHECK in base::internal::JSONParser.

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 <cmath>
 
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 291 matching lines @@
   std::swap(other->pos_, pos_);
   std::swap(other->length_, length_);
 }
 
 JSONParser::StringBuilder::~StringBuilder() {
   delete string_;
 }
 
 void JSONParser::StringBuilder::Append(const char& c) {
   DCHECK_GE(c, 0);
-  DCHECK_LT(c, 128);
+  DCHECK_LT(static_cast<unsigned char>(c), 128);
 
   if (string_)
     string_->push_back(c);
   else
     ++length_;
 }
 
 void JSONParser::StringBuilder::AppendString(const std::string& str) {
   DCHECK(string_);
   string_->append(str);
@@ skipping 651 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