Suppress a deadlock report through media::Pipeline::GetMediaTime.

BUG=407452
TBR=xhwang@chromium.org

Review URL: https://codereview.chromium.org/501283002

Cr-Commit-Position: refs/heads/master@{#291847}

build/sanitizers/tsan_suppressions.cc

@@ -302,6 +302,9 @@ char kTSanDefaultSuppressions[] =
 "deadlock:"
 "base::debug::TraceEventTestFixture_ThreadOnceBlocking_Test::TestBody\n"
 
+// http://crbug.com/407452
+"deadlock:media::Pipeline::GetMediaTime\n"
+
 // End of suppressions.
 ;  // Please keep this semicolon.