So this came out of https://chromium-review.googlesource.com/c/chromium/src/+/879469

Ethan, correct me if this description is incorrect.

Telemetry has a hack in the chartjson export that treats names with a "." differently. Specifically, it splits on the "." and exports it as chart/trace with the name retained as the original Foo.Bar. This messes with Pinpoint since histograms doesn't have this hack, and so the data only has a histogram named "Foo.Bar", not a histogram named "Foo" with a story "Bar" (chartjson).

Since these are different, Pinpoint can't find the values from the histogram data and any bisects on these older benchmarks fail.