Remove base's implicit_cast.

net/disk_cache/simple/simple_index_file.cc

 // Copyright (c) 2013 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 "net/disk_cache/simple/simple_index_file.h"
 
 #include <vector>
 
 #include "base/files/file.h"
 #include "base/files/file_util.h"
 #include "base/files/memory_mapped_file.h"
 #include "base/hash.h"
 #include "base/logging.h"
+#include "base/numerics/safe_conversions.h"
 #include "base/pickle.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner_util.h"
 #include "base/threading/thread_restrictions.h"
 #include "net/disk_cache/simple/simple_backend_version.h"
 #include "net/disk_cache/simple/simple_entry_format.h"
 #include "net/disk_cache/simple/simple_histogram_macros.h"
 #include "net/disk_cache/simple/simple_index.h"
 #include "net/disk_cache/simple/simple_synchronous_entry.h"
 #include "net/disk_cache/simple/simple_util.h"
@@ skipping 46 matching lines @@
 
 bool WritePickleFile(base::Pickle* pickle, const base::FilePath& file_name) {
   File file(
       file_name,
       File::FLAG_CREATE | File::FLAG_WRITE | File::FLAG_SHARE_DELETE);
   if (!file.IsValid())
     return false;
 
   int bytes_written =
       file.Write(0, static_cast<const char*>(pickle->data()), pickle->size());
-  if (bytes_written != implicit_cast<int>(pickle->size())) {
+  if (bytes_written != base::checked_cast<int>(pickle->size())) {
     simple_util::SimpleCacheDeleteFile(file_name);
     return false;
   }
   return true;
 }
 
 // Called for each cache directory traversal iteration.
 void ProcessEntryFile(SimpleIndex::EntrySet* entries,
                       const base::FilePath& file_path) {
   static const size_t kEntryFilesLength =
@@ skipping 383 matching lines @@
 bool SimpleIndexFile::LegacyIsIndexFileStale(
     base::Time cache_last_modified,
     const base::FilePath& index_file_path) {
   base::Time index_mtime;
   if (!simple_util::GetMTime(index_file_path, &index_mtime))
     return true;
   return index_mtime < cache_last_modified;
 }
 
 }  // namespace disk_cache