From 9469a9b8251972e0a53994685ae7a688f28ce843 Mon Sep 17 00:00:00 2001
From: Noemi Erli <nerli@mozilla.com>
Date: Wed, 26 May 2021 04:34:26 +0300
Subject: [PATCH] Backed out changeset 4c53c4da7ece (bug 1677555) for causing
 multiple failures in imgRequestProxy.cpp CLOSED TREE

---
 layout/style/nsStyleStruct.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index bf4ed243042a..92e4ae34e28a 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/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.