Remove suppressions for AtExitManager/Singleton races...

tools/valgrind/tsan/suppressions.txt

 ############################
 # Chromium
 
 {
   bug_23433
   ThreadSanitizer:Race
   fun:*logging*SetMinLogLevel*
 }
 
 {
@@ skipping 138 matching lines @@
   fun:talk_base::PhysicalSocketServer::~PhysicalSocketServer()
   fun:scoped_ptr<talk_base::SocketServer>::~scoped_ptr()
   fun:talk_base::MessageQueue::~MessageQueue()
   fun:talk_base::Thread::~Thread()
   fun:talk_base::ThreadManager::UnwrapCurrentThread()
   fun:talk_base::ThreadManager::~ThreadManager()
   fun:__tcf_0
   fun:exit
 }
 
-{
-  bug_61585a
-  ThreadSanitizer:UnlockForeign
-  fun:pthread_mutex_destroy
-  ...
-  fun:NSS_Shutdown
-  ...
-  fun:*AtExitManager*
-}
-
-{
-  bug_61585b
-  ThreadSanitizer:UnlockNonLocked
-  fun:pthread_mutex_unlock
-  fun:PR_Unlock
-  fun:nssSession_ExitMonitor
-  fun:find_objects
-  ...
-  fun:nssTrustDomain_FindCertificatesBySubject
-  ...
-}
-
-{
-  bug_61753
-  ThreadSanitizer:Race
-  ...
-  fun:*AtExitManager*
-}
-
 ############################
 # Data races in tests
 
 {
   bug_30582
   ThreadSanitizer:Race
   fun:*LongCallbackD*
   fun:*WorkerThreadTickerTest_LongCallback_Test*TestBody*
 }
 
@@ skipping 196 matching lines @@
   ThreadSanitizer:Race
   ...
   fun:gethostbyname2_r*
 }
 
 {
   Benign race in nss (PR_EnterMonitor)
   ThreadSanitizer:Race
   fun:PR_EnterMonitor
 }