[content]: Ensure TaskQueueManager AFTER_WAKEUP autopump policy wakes only on newer tasks.

content/renderer/scheduler/renderer_scheduler_impl_unittest.cc

 // Copyright 2014 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 "content/renderer/scheduler/renderer_scheduler_impl.h"
 
 #include "base/callback.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/test/ordered_simple_task_runner.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ skipping 296 matching lines @@
   EnableIdleTasks();  // Must start a new idle period before idle task runs.
   RunUntilIdle();
   // Execution of default task queue task should trigger execution of idle task.
   EXPECT_EQ(2, run_count);
 }
 
 TEST_F(RendererSchedulerImplTest, TestPostIdleTaskAfterWakeupWhileAwake) {
   base::TimeTicks deadline_in_task;
   int run_count = 0;
 
-  default_task_runner_->PostTask(FROM_HERE, base::Bind(&NullTask));
   idle_task_runner_->PostIdleTaskAfterWakeup(
       FROM_HERE, base::Bind(&IdleTestTask, &run_count, &deadline_in_task));
+  default_task_runner_->PostTask(FROM_HERE, base::Bind(&NullTask));
 
   RunUntilIdle();
   EnableIdleTasks();  // Must start a new idle period before idle task runs.
   RunUntilIdle();
   // Should run as the scheduler was already awakened by the normal task.
   EXPECT_EQ(1, run_count);
 }
 
 TEST_F(RendererSchedulerImplTest, TestPostIdleTaskWakesAfterWakeupIdleTask) {
   base::TimeTicks deadline_in_task;
@@ skipping 670 matching lines @@
   EXPECT_EQ(Policy::COMPOSITOR_PRIORITY, CurrentPolicy());
 
   // Process the input event with a new BeginMainFrame.
   DoMainFrame();
   clock_->AdvanceNow(2 * priority_escalation_after_input_duration());
   RunUntilIdle();
   EXPECT_EQ(Policy::NORMAL, CurrentPolicy());
 }
 
 }  // namespace content