Removed suppression for bug 243963.

tools/valgrind/tsan/suppressions.txt

 # There are a few 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 # running overnight and removing outdated bugs/suppressions.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 1139 matching lines @@
   fun:KiUserCallbackDispatcher
   fun:LoadStringA
   fun:LoadStringA
   fun:LoadStringA
   fun:CreateWindowExW
   fun:base::MessagePumpForUI::InitMessageWnd
   fun:base::MessagePumpForUI::MessagePumpForUI
   fun:base::MessageLoop::MessageLoop
   fun:remoting::AutoThread::ThreadMain
 }
-{
-  bug_243963
-  ThreadSanitizer:Race
-  fun:base::subtle::RefCountedBase::AddRef
-  fun:base::RefCounted::AddRef
-  fun:scoped_refptr::scoped_refptr
-  fun:base::internal::InvokeHelper::MakeItSo
-  fun:base::internal::Invoker::Run
-  fun:base::Callback::Run
-  fun:base::MessageLoop::RunTask
-  fun:base::MessageLoop::DeferOrRunPendingTask
-  fun:base::MessageLoop::DoWork
-  fun:base::MessagePumpLibevent::Run
-  fun:base::MessageLoop::RunInternal
-  fun:base::MessageLoop::RunHandler
-  fun:base::RunLoop::Run
-  fun:base::MessageLoop::Run
-  fun:base::Thread::Run
-  fun:content::BrowserThreadImpl::FileThreadRun
-  fun:content::BrowserThreadImpl::Run
-  fun:base::Thread::ThreadMain
-  fun:base::::ThreadFunc
-}