Affected version: 70.0.3531.0. 
I've also tested Chrome 68.0.3440.91 and the issue is here as well, but with slightly different logs.

Steps to reproduce:
1. Build chrome_public_apk
2. Install it on device
3. Start Chromium once, go through first run wizard
4. Kill Chromium process (swipe it off in recents)
5. Start Chromium once again

Expected result:
Locale PAKs aren't extracted during second startup because they are already on disk.

Actual result:
PAKs are extracted again (see second cr_FileUtils line in the log):

<First run>
08-23 13:50:06.545  15041 15154 org.chromium.chrome I cr_ui Using UI locale ru, system locale: ru (Android name: ru)
08-23 13:50:06.551  15041 15146 org.chromium.chrome I cr_tabmodel Starting to fetch tab list for tab_state0
08-23 13:50:06.552  15041 15146 org.chromium.chrome I cr_tabmodel Finished fetching tab list.
08-23 13:50:06.553  15041 15146 org.chromium.chrome I cr_tabmodel Starting to fetch tab list for tab_state_browser_actions
08-23 13:50:06.553  15041 15146 org.chromium.chrome I cr_tabmodel State file does not exist.
08-23 13:50:06.556  15041 15154 org.chromium.chrome I cr_ui Missing asset file: locales#lang_ru/ru.pak
08-23 13:50:06.562  15041 15154 org.chromium.chrome I cr_ui Found asset file: locales/ru.pak
08-23 13:50:06.562  15041 15154 org.chromium.chrome I cr_ui Using app bundle locale directory: locales
08-23 13:50:06.562  15041 15154 org.chromium.chrome I cr_ui UI Language: ru requires .pak files: [ru]
08-23 13:50:06.573  15041 15154 org.chromium.chrome I cr_FileUtils  Writing to /data/user/0/org.chromium.chrome/app_chrome/paks/ru.pak@165669e2a56
08-23 13:50:09.496  15041 15152 org.chromium.chrome I cr_LibraryLoader  Time to load native libraries: 3128 ms (timestamps 7946-1074)

<...Restart skipped...>

08-23 13:50:33.720  15439 15439 org.chromium.chrome I cr_base_multidex  Completed multidex installation.
08-23 13:50:34.012  15439 15478 org.chromium.chrome I cr_ui Using UI locale ru, system locale: ru (Android name: ru)
08-23 13:50:34.013  15439 15478 org.chromium.chrome I cr_ui Missing asset file: locales#lang_ru/ru.pak
08-23 13:50:34.014  15439 15478 org.chromium.chrome I cr_ui Found asset file: locales/ru.pak
08-23 13:50:34.014  15439 15478 org.chromium.chrome I cr_ui Using app bundle locale directory: locales
08-23 13:50:34.014  15439 15478 org.chromium.chrome I cr_ui UI Language: ru requires .pak files: [ru]
08-23 13:50:34.019  15439 15478 org.chromium.chrome I cr_FileUtils  Writing to /data/user/0/org.chromium.chrome/app_chrome/paks/ru.pak@165669e2a56
08-23 13:50:34.019  15439 15470 org.chromium.chrome I cr_tabmodel Starting to fetch tab list for tab_state0
08-23 13:50:34.027  15439 15478 org.chromium.chrome I cr_tabmodel Starting to fetch tab list for tab_state_browser_actions
08-23 13:50:34.041  15439 15470 org.chromium.chrome I cr_tabmodel Finished fetching tab list.
08-23 13:50:34.048  15439 15478 org.chromium.chrome I cr_tabmodel State file does not exist.
08-23 13:50:36.807  15439 15476 org.chromium.chrome I cr_LibraryLoader  Time to load native libraries: 2956 ms (timestamps 5428-8384)
08-23 13:50:36.807  15439 15476 org.chromium.chrome W chromium  [0823/135036.807630:WARNING:trace_startup_config.cc(188)] The trace config file does not exist.