Widen one HeapCheck suppression, fix one TSan suppression

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 # running overnight and removing outdated bugs/suppressions.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 688 matching lines @@
   fun:media::AudioRendererAlgorithmOLA::set_playback_rate
   fun:media::AudioRendererBase::SetPlaybackRate
   fun:AudioRendererImpl::SetPlaybackRate
   fun:media::CompositeFilter::SetPlaybackRate
   fun:media::PipelineImpl::PlaybackRateChangedTask
   ...
   fun:base::internal::RunnableAdapter::Run
 }
 {
   bug_107181b
+  ThreadSanitizer:Race
   fun:media::AudioRendererAlgorithmBase::playback_rate
   fun:media::AudioRendererBase::GetPlaybackRate
   fun:AudioRendererImpl::Render
   fun:AudioDevice::FireRenderCallback
   fun:AudioDevice::Run
 }