WipeDataHooks were used to avoid showing ClearDataProgressDialog if there's no data to be wiped during sign-out. However, now it's always shown, as at least ServiceWorker caches are wiped when the user is signed out. Thus, preWipeData can be safely removed and postWipeData can be merged with sign-out callback.

[1] https://cs.chromium.org/chromium/src/chrome/android/java/src/org/chromium/chrome/browser/signin/SigninManager.java?l=621&rcl=15ec33029e98655954d4ce2ab3cdf67e2f7577a1.