Fix race in INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO
Fix race in INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO

BUG=webrtc:7251

Review-Url: https://codereview.webrtc.org/2716343002
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#16862}

TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc