Backed out changeset 4c53c4da7ece (bug 1677555) for causing multiple failures in imgRequestProxy.cpp CLOSED TREE

layout/style/nsStyleStruct.cpp

@@ -188,10 +188,13 @@ class StyleImageRequestCleanupTask final : public mozilla::Runnable {
 // This is defined here for parallelism with LoadURI.
 void Gecko_LoadData_Drop(StyleLoadData* aData) {
   if (aData->resolved_image) {
-    // We want to dispatch this async to prevent reentrancy issues, as
-    // imgRequestProxy going away can destroy documents, etc, see bug 1677555.
     auto task = MakeRefPtr<StyleImageRequestCleanupTask>(*aData);
-    SchedulerGroup::Dispatch(TaskCategory::Other, task.forget());
+    if (NS_IsMainThread()) {
+      task->Run();
+    } else {
+      // if Resolve was not called at some point, mDocGroup is not set.
+      SchedulerGroup::Dispatch(TaskCategory::Other, task.forget());
+    }
   }
 
   // URIs are safe to refcount from any thread.