Fix a couple of data races found by TSAN Race Verifier in VideoCaptureController.

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 # running overnight and removing outdated bugs/suppressions.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 496 matching lines @@
 }
 
 {
   bug_72548
   ThreadSanitizer:Race
   ...
   fun:JSC::Yarr::Interpreter::*Disjunction*
   fun:JSC::Yarr::Interpreter::interpret*
   fun:JSC::Yarr::interpret*
 }
-{
-  bug_86507
-  ThreadSanitizer:Race
-  fun:VideoCaptureController::OnDeviceStopped
-}
 
 {
   bug_86916
   ThreadSanitizer:Race
   fun:loopfilter_frame
   fun:loopfilter_thread
 }
 
 {
   bug_87062a
@@ skipping 144 matching lines @@
 }
 {
    bug_95509
    ThreadSanitizer:Race
    fun:base::SyncSocket::Close
    fun:AudioRendererImpl::OnStop
    fun:media::AudioRendererBase::Stop
    fun:media::CompositeFilter::CallFilter
    fun:media::CompositeFilter::SerialCallback
 }