Bug 1764419 - Fix reuse of empty HitTestInfo. r=gfx-reviewers,bradwerth

Differential Revision: https://phabricator.services.mozilla.com/D143543

layout/painting/HitTestInfo.cpp

@@ -19,7 +19,7 @@ namespace mozilla {
 static StaticAutoPtr<const HitTestInfo> gEmptyHitTestInfo;
 
 const HitTestInfo& HitTestInfo::Empty() {
-  if (gEmptyHitTestInfo) {
+  if (!gEmptyHitTestInfo) {
     gEmptyHitTestInfo = new HitTestInfo();
   }