Chris Bracken bd8e431d79 Restrict timeline collection to a subset of demos (#9093)
Also refactors demos list into a class with `synchronized` and
`profiled` properties.

When run with --trace-startup, as we do in this test, the VM stores
trace events in an endless buffer instead of a ring buffer. To avoid
out-of-memory conditions, we restrict timeline collection to a subset.
2017-03-29 19:12:50 -07:00
..