Fix Brave Ads base::Time::FromLocalExplode always returns false from Linux sandbox on non UTC+0 timezones

[aseren]

base::Time::FromLocalExpolode uses libc mktime call which requires access to /etc/timezone file: https://source.chromium.org/chromium/chromium/src/+/main:base/time/time_exploded_posix.cc;l=107?q=time_exploded_pos&ss=chromium
But access to filesystem is restricted from sandbox, so mktime uses UTC+0 timezone.

The problem is that base::Time::FromLocalExpolode verifies the results of mktime using base::Time::LocalExpolode function which uses local timezone (not UTC+0), because it calls libc localtime_r function. In fact localtime_r function call is intercepted in browser process thus returns time in local timezone. See:
https://bugs.chromium.org/p/chromium/issues/detail?id=16800
https://codereview.chromium.org/165011
https://source.chromium.org/chromium/chromium/src/+/main:sandbox/linux/services/libc_interceptor.cc;l=225?q=libc_interce&ss=chromium

So if local timezone is not UTC+0 then verification step fails and base::Time::FromLocalExpolode always returns false here:
https://source.chromium.org/chromium/chromium/src/+/main:base/time/time_exploded_posix.cc;l=283?q=time_exploded_pos&ss=chromium

[btlechowski]

The corresponding PR has been merged. This issue can be closed.

[tmancey]

Blocked until ads has moved to the browser process 100%

[tmancey]

CHECKs were triggered so brave/brave-core#20627 removes those CHECKs.

[tmancey]

Closing as won't fix

[tmancey]

@aseren are we sure the linked bugs are related because they are 14 years old?

[tmancey]

Resolved by #39307