dead code removal
diff --git a/src/core/lib/iomgr/exec_ctx.cc b/src/core/lib/iomgr/exec_ctx.cc
index f45def4..a847b4d 100644
--- a/src/core/lib/iomgr/exec_ctx.cc
+++ b/src/core/lib/iomgr/exec_ctx.cc
@@ -53,13 +53,6 @@
 
 static gpr_timespec g_start_time;
 
-// For debug of the timer manager crash only.
-// TODO (mxyan): remove after bug is fixed.
-#ifdef GRPC_DEBUG_TIMER_MANAGER
-extern int64_t g_start_time_sec;
-extern int64_t g_start_time_nsec;
-#endif  // GRPC_DEBUG_TIMER_MANAGER
-
 static grpc_millis timespec_to_millis_round_down(gpr_timespec ts) {
   ts = gpr_time_sub(ts, g_start_time);
   double x = GPR_MS_PER_SEC * static_cast<double>(ts.tv_sec) +
@@ -125,12 +118,6 @@
 
 void ExecCtx::GlobalInit(void) {
   g_start_time = gpr_now(GPR_CLOCK_MONOTONIC);
-  // For debug of the timer manager crash only.
-  // TODO (mxyan): remove after bug is fixed.
-#ifdef GRPC_DEBUG_TIMER_MANAGER
-  g_start_time_sec = g_start_time.tv_sec;
-  g_start_time_nsec = g_start_time.tv_nsec;
-#endif
   gpr_tls_init(&exec_ctx_);
 }