Add static tracepoint to ContextStack event handlers
Add static tracepoint to ContextStack event handlers

Summary: Add static tracepoint to ContextStack event handlers

Reviewed By: yfeldblum

Differential Revision: D8984418

fbshipit-source-id: 2ee0cd14f9899f0d3502f9c29c5fcc88342278d2

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift