Require explicit selection of traits for LazyInstance

ui/accessibility/platform/ax_platform_node_win.cc

Index: ui/accessibility/platform/ax_platform_node_win.cc
diff --git a/ui/accessibility/platform/ax_platform_node_win.cc b/ui/accessibility/platform/ax_platform_node_win.cc
index 428222ef6664e2b97b1c54e7eac3e35e82c884b8..00fd88db91ad283a0f6359ae1abc3cf380a90d37 100644
--- a/ui/accessibility/platform/ax_platform_node_win.cc
+++ b/ui/accessibility/platform/ax_platform_node_win.cc
@@ -83,7 +83,7 @@ namespace {
 typedef base::hash_set<AXPlatformNodeWin*> AXPlatformNodeWinSet;
 // Set of all AXPlatformNodeWin objects that were the target of an
 // alert event.
-base::LazyInstance<AXPlatformNodeWinSet> g_alert_targets =
+base::LazyInstance<AXPlatformNodeWinSet>::DestructorAtExit g_alert_targets =
     LAZY_INSTANCE_INITIALIZER;
 
 base::LazyInstance<base::ObserverList<IAccessible2UsageObserver>>