Make IdleTimeEstimator ignore nested tasks

components/scheduler/renderer/idle_time_estimator_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/renderer/idle_time_estimator.h"
 
 #include "base/test/simple_test_tick_clock.h"
 #include "cc/test/ordered_simple_task_runner.h"
 #include "components/scheduler/base/task_queue_manager.h"
 #include "components/scheduler/base/test_time_source.h"
@@ skipping 125 matching lines @@
 }
 
 TEST_F(IdleTimeEstimatorTest, Estimation_MultipleTasks) {
   SimulateFrameWithTwoCompositorTasks(1, 4);
   SimulateFrameWithTwoCompositorTasks(1, 4);
 
   EXPECT_EQ(base::TimeDelta::FromMilliseconds(11),
             estimator_->GetExpectedIdleDuration(frame_length_));
 }
 
+TEST_F(IdleTimeEstimatorTest, IgnoresNestedTasks) {
+  SimulateFrameWithOneCompositorTask(5);
+  SimulateFrameWithOneCompositorTask(5);
+
+  base::PendingTask task(FROM_HERE, base::Closure());
+  estimator_->WillProcessTask(task);
+  SimulateFrameWithTwoCompositorTasks(4, 4);
+  SimulateFrameWithTwoCompositorTasks(4, 4);
+  SimulateFrameWithTwoCompositorTasks(4, 4);
+  SimulateFrameWithTwoCompositorTasks(4, 4);
+  estimator_->DidCommitFrameToCompositor();
+  estimator_->DidProcessTask(task);
+
+  EXPECT_EQ(base::TimeDelta::FromMilliseconds(11),
+            estimator_->GetExpectedIdleDuration(frame_length_));
+}
+
+
 }  // namespace scheduler