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