Hide ScopedTrace.

(cherry-pick of f2c1e7ee78a167ff323b9f45d20532d064d6778d.)

Bug: 11156955

(cherry picked from commit ebb6b4a4d3fab87800b912c9d6ea917f5359f8af)

Change-Id: Ifc10364b35384a9f34e4c2c634dd78a16065a817
1 file changed