google/tracing-framework — pull request #475 by mpd (2014-05-12 22:58:38+00:00)
Title: Load each source serially.

Since Database.beginInsertinEvents assumes that its operating on one
source at a time, we need to serialize the source loading instead of
doing it in parallel.

This fixes the assertion that fires in debug mode when loading a worker
trace alongside a main trace.