Try a different way of unregistering TaskQueues from ThrottlingHelper

components/scheduler/renderer/throttling_helper.cc

Index: components/scheduler/renderer/throttling_helper.cc
diff --git a/components/scheduler/renderer/throttling_helper.cc b/components/scheduler/renderer/throttling_helper.cc
index 107035d65e081bd52fbc9c0afdf8a1268d1f45ea..54baacc8cff478a43a6896a62f636e34ebc0b4c8 100644
--- a/components/scheduler/renderer/throttling_helper.cc
+++ b/components/scheduler/renderer/throttling_helper.cc
@@ -79,6 +79,10 @@ void ThrottlingHelper::DecreaseThrottleRefCount(TaskQueue* task_queue) {
   }
 }
 
+void ThrottlingHelper::UnregisterTaskQueue(TaskQueue* task_queue) {
+  throttled_queues_.erase(task_queue);
+}
+
 void ThrottlingHelper::OnTimeDomainHasImmediateWork() {
   // Forward to the main thread if called from another thread.
   if (!task_runner_->RunsTasksOnCurrentThread()) {