1 // Copyright 2019 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef CHROME_BROWSER_CHROMEOS_STARTUP_SETTINGS_CACHE_H_
6 #define CHROME_BROWSER_CHROMEOS_STARTUP_SETTINGS_CACHE_H_
7 
8 #include <string>
9 
10 namespace chromeos {
11 namespace startup_settings_cache {
12 
13 // On Chrome OS, the application locale is stored in local state prefs. The
14 // zygote needs the locale so it can load the correct resource bundle and
15 // provide localized strings to renderers. However, the zygote forks and engages
16 // the sandbox before the browser loads local state.
17 //
18 // Instead, cache the locale in a separate JSON file and read it on zygote
19 // startup. The additional disk read on startup is unfortunately, but it's only
20 // ~20 bytes and this approach performs better than other approaches (passing a
21 // resource bundle file descriptor to zygote on renderer fork, or pre-load the
22 // local state file on startup). On coral (dual core Celeron N3350 1.1 GHz) the
23 // file read takes < 2.5 ms and the write takes < 1 ms. https://crbug.com/510455
24 std::string ReadAppLocale();
25 
26 // Writes the locale string to a JSON file on disk. See above.
27 void WriteAppLocale(std::string app_locale);
28 
29 }  // namespace startup_settings_cache
30 }  // namespace chromeos
31 
32 #endif  // CHROME_BROWSER_CHROMEOS_STARTUP_SETTINGS_CACHE_H_
33