Reland of Enable C4018 globally for the GN build, and disable per-target.

components/filesystem/file_impl.cc

 // Copyright 2015 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 "components/filesystem/file_impl.h"
 
 #include <stdint.h>
 #include <limits>
 
 #include "base/files/file_path.h"
@@ skipping 84 matching lines @@
                      const WriteCallback& callback) {
   DCHECK(!bytes_to_write.is_null());
   if (!file_.IsValid()) {
     callback.Run(GetError(file_), 0);
     return;
   }
   // Who knows what |write()| would return if the size is that big (and it
   // actually wrote that much).
   if (bytes_to_write.size() >
 #if defined(OS_WIN)
-      std::numeric_limits<INT>::max()) {
+      static_cast<size_t>(std::numeric_limits<int>::max())) {
 #else
       static_cast<size_t>(std::numeric_limits<ssize_t>::max())) {
 #endif
     callback.Run(FILE_ERROR_INVALID_OPERATION, 0);
     return;
   }
   if (FileError error = IsOffsetValid(offset)) {
     callback.Run(error, 0);
     return;
   }
@@ skipping 186 matching lines @@
       new_file.TakePlatformFile(), &mojo_handle);
   if (create_result != MOJO_RESULT_OK) {
     callback.Run(FILE_ERROR_FAILED, ScopedHandle());
     return;
   }
 
   callback.Run(FILE_ERROR_OK, ScopedHandle(mojo::Handle(mojo_handle)).Pass());
 }
 
 }  // namespace filesystem