GitLab

crrev.com/933613002 introduced a ODR violtaion by adding the
DeleteForTesting method (other definition in trace_event_impl.cc).
This was causing an ASan assertion (see crbug.com/459556) and failures
of base_unittests in debug builds (see crrev.com/933613002 #33).
This CL fixes the DeleteForTesting pattern removing the awkward ODR
violation.

BUG=459556,458295
TBR=nduca@chromium.org

Review URL: https://codereview.chromium.org/942803002

Cr-Commit-Position: refs/heads/master@{#317316}