Adjust tsan suppressions for media::Pipeline due to r156011.

media/base/pipeline.cc

Index: media/base/pipeline.cc
diff --git a/media/base/pipeline.cc b/media/base/pipeline.cc
index 31ccf58a3978f84a81c9c76e09729b02d7ad5b4a..2cb87f00d3890569af7602262bcffba8c03cf799 100644
--- a/media/base/pipeline.cc
+++ b/media/base/pipeline.cc
@@ -360,6 +360,8 @@ void Pipeline::OnAudioTimeUpdate(TimeDelta time, TimeDelta max_time) {
   if (waiting_for_clock_update_ && time < clock_->Elapsed())
     return;
 
+  // TODO(scherkus): |state_| should only be accessed on pipeline thread, see
+  // http://crbug.com/137973
   if (state_ == kSeeking)
     return;
 
@@ -374,6 +376,8 @@ void Pipeline::OnVideoTimeUpdate(TimeDelta max_time) {
   if (has_audio_)
     return;
 
+  // TODO(scherkus): |state_| should only be accessed on pipeline thread, see
+  // http://crbug.com/137973
   if (state_ == kSeeking)
     return;