Fix potential DCHECK in TaskQueueThrottler::IncreaseThrottleRefCount

third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc

Index: third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc
index fee7f311ab1eb2885fe4cf5c7f51be0844a82e76..742f845ba65bda18adc3e1ffe093d88567620901 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc
@@ -803,6 +803,17 @@ void TaskQueueImpl::EnableOrDisableWithSelector(bool enable) {
     return;
 
   if (enable) {
+    // Check if there's any immediate work on either queue.
+    bool immediate_queues_empty =
+        main_thread_only().immediate_work_queue->Empty();
+    if (immediate_queues_empty) {
+      base::AutoLock lock(any_thread_lock_);
+      immediate_queues_empty = any_thread().immediate_incoming_queue.empty();
+    }
+    // Avoid holding the lock while we fire the notification.
+    if (!immediate_queues_empty)
+      main_thread_only().time_domain->OnQueueHasImmediateWork(this);
+
     if (!main_thread_only().delayed_incoming_queue.empty()) {
       main_thread_only().time_domain->ScheduleDelayedWork(
           this,