Bug 1786818. r=mstange

Differential Revision: https://phabricator.services.mozilla.com/D155462

dom/base/nsDOMWindowUtils.cpp

@@ -2803,7 +2803,7 @@ nsDOMWindowUtils::AdvanceTimeAndRefresh(int64_t aMilliseconds) {
 
   nsPresContext* presContext = GetPresContext();
   if (presContext) {
-    nsRefreshDriver* driver = presContext->RefreshDriver();
+    RefPtr<nsRefreshDriver> driver = presContext->RefreshDriver();
     driver->AdvanceTimeAndRefresh(aMilliseconds);
 
     if (WebRenderBridgeChild* wrbc = GetWebRenderBridge()) {

image/SVGDocumentWrapper.cpp

@@ -180,7 +180,9 @@ void SVGDocumentWrapper::SetCurrentTime(float aTime) {
 void SVGDocumentWrapper::TickRefreshDriver() {
   if (RefPtr<PresShell> presShell = mViewer->GetPresShell()) {
     if (RefPtr<nsPresContext> presContext = presShell->GetPresContext()) {
-      presContext->RefreshDriver()->DoTick();
+      if (RefPtr<nsRefreshDriver> driver = presContext->RefreshDriver()) {
+        driver->DoTick();
+      }
     }
   }
 }