Suppress a race from passing MessageLoopRunner::QuitClosure() to another thread.

TBR=jam@chromium.org
BUG=454655

Review URL: https://codereview.chromium.org/943763003

Cr-Commit-Position: refs/heads/master@{#317170}

build/sanitizers/tsan_suppressions.cc

@@ -331,6 +331,9 @@ char kTSanDefaultSuppressions[] =
 // https://crbug.com/460243
 "race:IPC::ChannelMojoHost::OnClientLaunched\n"
 
+// https://crbug.com/454655
+"race:content::BrowserTestBase::PostTaskToInProcessRendererAndWait\n"
+
 // End of suppressions.
 ;  // Please keep this semicolon.