scheduler: Remove task observer shenanigans

components/scheduler/child/idle_helper_unittest.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 "components/scheduler/child/idle_helper.h"
 
 #include "base/callback.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "cc/test/ordered_simple_task_runner.h"
 #include "components/scheduler/child/scheduler_helper.h"
@@ skipping 808 matching lines @@
   RunUntilIdle();
   EXPECT_EQ(1, run_count);
   clock_->Advance(idle_task_duration);
 
   // Next idle period shouldn't happen until the pending task has been run.
   RunUntilIdle();
   EXPECT_EQ(1, run_count);
 
   // Once the pending task is run the new idle period should start.
   clock_->Advance(pending_task_delay - idle_task_duration);
-  RunUntilIdle();
+
   // Since the idle period tried to start before the pending task ran we have to
   // wait for the idle helper to retry starting the long idle period.
   clock_->Advance(retry_enable_long_idle_period_delay());
   RunUntilIdle();
 
   EXPECT_EQ(2, run_count);
   EXPECT_EQ(expected_deadline, actual_deadline);
 }
 
 TEST_F(IdleHelperTest, TestLongIdlePeriodPaused) {
@@ skipping 297 matching lines @@
   EXPECT_EQ(0, run_count);
 
   default_task_runner_->PostDelayedTask(FROM_HERE, base::Bind(&NullTask),
                                         more_than_min_deadline_duration);
   idle_helper_->EnableLongIdlePeriod();
   RunUntilIdle();
   EXPECT_EQ(1, run_count);
 }
 
 }  // namespace scheduler