scheduler: Disable expensive timers during main thread user input

components/scheduler/renderer/task_cost_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 "base/test/simple_test_tick_clock.h"
+#include "components/scheduler/renderer/task_cost_estimator.h"
+
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace scheduler {
+
+class TaskCostEstimatorTest : public testing::Test {
+ public:
+  TaskCostEstimatorTest() {}
+  ~TaskCostEstimatorTest() override {}
+
+  void SetUp() override {}
+
+  base::SimpleTestTickClock clock_;
+};
+
+class TaskCostEstimatorForTest : public TaskCostEstimator {
+ public:
+  TaskCostEstimatorForTest(base::SimpleTestTickClock* clock,
+                           int sample_count,
+                           double estimation_percentile)
+      : TaskCostEstimator(sample_count, estimation_percentile), clock_(clock) {}
+
+ protected:
+  base::TimeTicks Now() override { return clock_->NowTicks(); }
+
+ private:
+  base::SimpleTestTickClock* clock_;
+};
+
+TEST_F(TaskCostEstimatorTest, BasicEstimation) {
+  TaskCostEstimatorForTest estimator(&clock_, 1, 100);
+  base::PendingTask task(FROM_HERE, base::Closure());
+
+  estimator.WillProcessTask(task);
+  clock_.Advance(base::TimeDelta::FromMilliseconds(500));
+  estimator.DidProcessTask(task);
+
+  EXPECT_EQ(base::TimeDelta::FromMilliseconds(500),
+            estimator.expected_task_duration());
+};
+
+TEST_F(TaskCostEstimatorTest, NestedRunLoop) {
+  TaskCostEstimatorForTest estimator(&clock_, 1, 100);
+  base::PendingTask task(FROM_HERE, base::Closure());
+
+  // Make sure we ignore the tasks inside the nested run loop.
+  estimator.WillProcessTask(task);
+  estimator.WillProcessTask(task);
+  clock_.Advance(base::TimeDelta::FromMilliseconds(500));
+  estimator.DidProcessTask(task);
+  clock_.Advance(base::TimeDelta::FromMilliseconds(500));
+  estimator.DidProcessTask(task);
+
+  EXPECT_EQ(base::TimeDelta::FromMilliseconds(1000),
+            estimator.expected_task_duration());
+};
+
+}  // namespace scheduler