This currently passed CI without it, because:
1. Profiler::instance() uses 'global' instead of Config::get(),
which means there is no warning for it being undefined. (When you
run a stament like 'global $foo' it implicitly auto-creates the
variable and assign it the null value).
2. Profiler::instance() uses array_merge() which silently tolerates
non-array values like null in the list of arguments.
This is changing in I638d9a219df7.
Bug: T247777
Change-Id: Ic77d6023ef88ad928fe5bf9807e6e8dfb7bc4e9c
Instead, the constructors for FileJournal and NullFileJournal should be
treated as stable. I would have added @stable, but our linting doesn't
recognize it yet and doesn't let.
Bug: T235066
Change-Id: I7741055b4f00197d1346ebbfebc14f20238a06f3
