This problem is actually easy to fix. The logs already exist, but they just aren't being put there.

 

This makes it really difficult to figure out what is going on on the waterfall. See https://chrome-isolated.appspot.com/browse?namespace=default-gzip&hash=26ea4e13d253cc91b55701074e678a3e8f14a86c

We don't that the perf logs that produce that perf json data, so we can't easily figure out what is going on with them.

This problem is actually easy to fix. The logs already exist, but they just aren't being put there.