[scheduler] Always run task queue observer callback for delayed work.

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/scheduler/base/task_queue_impl.h"
 
 #include <utility>
 
 #include "base/format_macros.h"
 #include "base/memory/ptr_util.h"
@@ skipping 872 matching lines @@
 void TaskQueueImpl::ScheduleDelayedWorkInTimeDomain(base::TimeTicks now) {
   if (!IsQueueEnabled())
     return;
   if (main_thread_only().delayed_incoming_queue.empty())
     return;
 
   main_thread_only().time_domain->ScheduleDelayedWork(
       this, main_thread_only().delayed_incoming_queue.top().delayed_wake_up(),
       now);
 
-  if (!HasPendingImmediateWork()) {
-    NotifyWakeUpChangedOnMainThread(
-        main_thread_only().delayed_incoming_queue.top().delayed_run_time);
-  }
+  NotifyWakeUpChangedOnMainThread(
+      main_thread_only().delayed_incoming_queue.top().delayed_run_time);
 }
 
 void TaskQueueImpl::NotifyWakeUpChangedOnMainThread(base::TimeTicks wake_up) {
   if (main_thread_only().observer)
     main_thread_only().observer->OnQueueNextWakeUpChanged(this, wake_up);
 }
 
 }  // namespace internal
 }  // namespace scheduler
 }  // namespace blink