These are guidelines from bpastene@:
"
In short, what's needed for stack trace symbolization is the logcats and tombstones generated on the device during the test. Consequently, the perf swarming tests need to capture these things from the device and either:
a) symbolize them within the swarming test.
or
b) upload/isolate them and have a subsequent recipe step download and symbolize them.

This is precisely what Emily outlined in the doc: https://docs.google.com/document/d/1CAHzQlCueCZUNNDiCK9HwjNWBm6wjut5012K3PTVoAQ/edit#heading=h.bumchbgwledy

Regardless of which option you chose, you'll need to add logic to the perf tests to capture the logcats and tombstones from the device. (From reading the doc, it sounded like Emily was thinking of creating some type of test wrapper to do this.) For reference, functional android swarming tests capture logcats via a background monitor that gets spawned at the beginning of the test which collects the logs into a file that swarming then isolates at the end of the test. (example) So you could potentially reuse some of the functionality there."