We suspect that the Catapult Mac Tryserver (https://build.chromium.org/p/tryserver.client.catapult/builders/Catapult%20Mac%20Tryserver) is not syncing to the latest CL. 

As seen in that link, a test on it continues to fail with:

TraceImportError: No clock sync markers exist pairing clock domain "UNKNOWN_CHROME_LEGACY" with model clock domain "TELEMETRY".
    at Object.getModelTimeTransformerRaw_ (/tracing/model/clock_sync_manager.html:171:15)
    at Object.getModelTimeTransformer (/tracing/model/clock_sync_manager.html:151:19)
    at Object.toModelTimeFromUs_ (/tracing/extras/importer/trace_event_importer.html:3052:42)
    at Object.processCompleteEvent (/tracing/extras/importer/trace_event_importer.html:522:16)
    at Object.importEvents (/tracing/extras/importer/trace_event_importer.html:1000:28)
    at Object.runImportEventsOnOneImporter (/tracing/importer/import.html:189:26)
    at Object.timedNamedFunction (/tracing/base/timing.html:70:18)
    at Object.run (/tracing/base/task.html:71:21)
    at Function.Task.RunSynchronously (/tracing/base/task.html:152:25)
    at Object.importTraces (/tracing/importer/import.html:73:17)

However, that bug was fixed with https://codereview.chromium.org/2332213008/ yesterday. I've confirmed this by syncing to that CL and running the test, both alone and with other tests, both of which pass. Infra-troopers, is there any way that you can check to see whether this bot is stuck or not?