Revert "Track thread activities in order to diagnose hangs."

base/synchronization/lock_impl_win.cc

Index: base/synchronization/lock_impl_win.cc
diff --git a/base/synchronization/lock_impl_win.cc b/base/synchronization/lock_impl_win.cc
index 31f95f4e394ba6af3bc52e8b4472251a7d35740b..d89a131a7a8a8fb84950baaaf572334e36fa85b8 100644
--- a/base/synchronization/lock_impl_win.cc
+++ b/base/synchronization/lock_impl_win.cc
@@ -4,8 +4,6 @@
 
 #include "base/synchronization/lock_impl.h"
 
-#include "base/debug/activity_tracker.h"
-
 namespace base {
 namespace internal {
 
@@ -18,7 +16,6 @@ bool LockImpl::Try() {
 }
 
 void LockImpl::Lock() {
-  base::debug::ScopedLockAcquireActivity lock_activity(this);
   ::AcquireSRWLockExclusive(&native_handle_);
 }