GitLab

This is the last stage of the trace_event directory restructuring.
This is part of a set of 3 CLs which is moving tracing clients to use
the new base::trace_debug namespace.
See crrev.com/837303004 and the related bug for motivations.

BUG=451032
TBR=nduca@chromium.org

Review URL: https://codereview.chromium.org/879913002

Cr-Commit-Position: refs/heads/master@{#315335}