Suppress a race on ChannelMojoHost::ChannelDelegate's WeakPtrFactory.

TBR=morrita@chromium.org
BUG=460243

Review URL: https://codereview.chromium.org/941063002

Cr-Original-Commit-Position: refs/heads/master@{#317157}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: f6cf0acfc90134b3579bec5a8c1f3163618de7ac

sanitizers/tsan_suppressions.cc

@@ -328,6 +328,9 @@ char kTSanDefaultSuppressions[] =
 // https://crbug.com/459429
 "race:randomnessPid\n"
 
+// https://crbug.com/460243
+"race:IPC::ChannelMojoHost::OnClientLaunched\n"
+
 // End of suppressions.
 ;  // Please keep this semicolon.