Revert "performance: Add concurrency and timer support to PerfLock."

This reverts commit abf737f90d9c8746b0833fe5ac43c195d1f095dc.
Revert "performance: Add Performance class and PerfLock API."

This reverts commit b3d046a7d96bc4e8affaa1b76de9b4a03a66e31b.