Remove TSan suppression that has been fixed by moving plugin dlopen()ing out-of-process.

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 # running overnight and removing outdated bugs/suppressions.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 489 matching lines @@
 }
 {
   bug_89141
   ThreadSanitizer:Race
   fun:base::Thread::message_loop
   fun:content::BrowserThread::IsMessageLoopValid
   fun:ThreadWatcherList::StartWatching
   fun:ThreadWatcherList::InitializeAndStartWatching
 }
 {
-  bug_93757_a
-  ThreadSanitizer:Race
-  fun:__memset_sse2
-  fun:VisitedLinkMaster::CreateURLTable
-}
-{
-  bug_93757_b
-  ThreadSanitizer:Race
-  ...
-  fun:webkit::npapi::PluginLib::ReadWebPluginInfo
-  fun:webkit::npapi::PluginList::ReadPluginInfo
-  fun:webkit::npapi::PluginList::LoadPlugin
-  fun:webkit::npapi::PluginList::LoadPluginsFromDir
-  fun:webkit::npapi::PluginList::LoadPluginsInternal
-  fun:webkit::npapi::PluginList::LoadPlugins
-  fun:webkit::npapi::PluginList::GetPlugins
-  fun:PluginService::GetPluginsInternal
-}
-{
   bug_93932_a
   ThreadSanitizer:Race
   ...
   fun:avcodec_close
   ...
   fun:media::FFmpegVideoDecodeEngine::Uninitialize
   ...
   fun:media::FFmpegVideoDecode*Test::*
 }
 {
@@ skipping 136 matching lines @@
   fun:webrtc::TracePosix::AddTime
   fun:webrtc::TraceImpl::AddImpl
   fun:webrtc::Trace::Add
   fun:webrtc::ThreadPosix::Run
 }
 {
   bug_103711f
   ThreadSanitizer:Race
   fun:WebRTCAudioDeviceTest::SetUp
 }