Fix compilation of build_utf8_validator_tables on Win64.

base/i18n/build_utf8_validator_tables.cc

 // Copyright 2014 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.
 
 // Create a state machine for validating UTF-8. The algorithm in brief:
 // 1. Convert the complete unicode range of code points, except for the
 //    surrogate code points, to an ordered array of sequences of bytes in
 //    UTF-8.
 // 2. Convert individual bytes to ranges, starting from the right of each byte
 //    sequence. For each range, ensure the bytes on the left and the ranges
@@ skipping 22 matching lines @@
 #include <algorithm>
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
+#include "base/safe_numerics.h"
 #include "base/strings/stringprintf.h"
 #include "third_party/icu/source/common/unicode/utf8.h"
 
 namespace {
 
 const char kHelpText[] =
     "Usage: build_utf8_validator_tables [ --help ] [ --output=<file> ]\n";
 
 const char kProlog[] =
     "// Copyright 2013 The Chromium Authors. All rights reserved.\n"
@@ skipping 257 matching lines @@
   const uint8 target_state = where == state_map->end()
                                  ? MakeState(rest, states, state_map)
                                  : where->second;
   DCHECK_LT(0, range.from());
   DCHECK_LT(range.to(), 0xFF);
   const StateRange new_state_initializer[] = {
       {0, 1}, {range.from(), target_state}, {range.to() + 1, 1}};
   states->push_back(
       State(new_state_initializer,
             new_state_initializer + arraysize(new_state_initializer)));
-  const uint8 new_state_number = states->size() - 1;
+  const uint8 new_state_number =
+      base::checked_numeric_cast<uint8>(states->size() - 1);
   CHECK(state_map->insert(std::make_pair(set, new_state_number)).second);
   return new_state_number;
 }
 
 std::vector<State> GenerateStates(const PairVector& pairs) {
   // States 0 and 1 are the initial/valid state and invalid state, respectively.
   std::vector<State> states(2, GenerateInvalidState());
   StateMap state_map;
   state_map.insert(std::make_pair(StringSet(), 0));
   for (PairVector::const_iterator it = pairs.begin(); it != pairs.end(); ++it) {
@@ skipping 123 matching lines @@
   PrintStates(states, output);
 
   if (!filename.empty()) {
     if (!base::CloseFile(output))
       PLOG(FATAL) << "Couldn't finish writing '" << filename.AsUTF8Unsafe()
                   << "'";
   }
 
   return EXIT_SUCCESS;
 }