Delete old user manager in ~ScopedTestCrosSettings

tools/heapcheck/suppressions.txt

 # There are three kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 1867 matching lines @@
    fun:cc::DelayBasedTimeSource::OnTimerFired
 }
 {
    bug_232777
    Heapcheck:Leak
    ...
    fun:net::QuicStreamFactory::GetOrCreateCryptoConfig
    fun:net::QuicStreamFactory::CreateSession
    fun:net::QuicStreamFactory::Job::DoConnect
 }
-{
-   bug_232924
-   Heapcheck:Leak
-   ...
-   fun:UserManagerImpl
-   fun:chromeos::UserManagerImplWrapper::get
-   fun:chromeos::UserManager::Get
-}