Prevent multiple pending UpdatePolicy tasks.

content/renderer/scheduler/deadline_task_runner_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 "content/renderer/scheduler/deadline_task_runner.h"
+
+#include "cc/test/ordered_simple_task_runner.h"
+#include "cc/test/test_now_source.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace content {
+
+class DeadlineTaskRunnerTest : public testing::Test {
+ public:
+  DeadlineTaskRunnerTest() {}
+  ~DeadlineTaskRunnerTest() override {}
+
+  void SetUp() override {
+    clock_ = cc::TestNowSource::Create(5000);
+    mock_task_runner_ = new cc::OrderedSimpleTaskRunner(clock_, true);
+    deadline_task_runner_.reset(new DeadlineTaskRunner(
+        base::Bind(&DeadlineTaskRunnerTest::TestTask, base::Unretained(this)),
+        mock_task_runner_));
+    run_times_.clear();
+  }
+
+  bool RunUntilIdle() { return mock_task_runner_->RunUntilIdle(); }
+
+  void TestTask() { run_times_.push_back(clock_->Now()); }
+
+  scoped_refptr<cc::TestNowSource> clock_;
+  scoped_refptr<cc::OrderedSimpleTaskRunner> mock_task_runner_;
+  scoped_ptr<DeadlineTaskRunner> deadline_task_runner_;
+  std::vector<base::TimeTicks> run_times_;
+};
+
+TEST_F(DeadlineTaskRunnerTest, RunOnce) {
+  base::TimeTicks start_time = clock_->Now();
+  base::TimeDelta delay = base::TimeDelta::FromMilliseconds(10);
+  deadline_task_runner_->SetDeadline(FROM_HERE, delay, clock_->Now());
+  RunUntilIdle();
+
+  EXPECT_THAT(run_times_, testing::ElementsAre(start_time + delay));
+};
+
+TEST_F(DeadlineTaskRunnerTest, RunTwice) {
+  base::TimeDelta delay1 = base::TimeDelta::FromMilliseconds(10);
+  base::TimeTicks deadline1 = clock_->Now() + delay1;
+  deadline_task_runner_->SetDeadline(FROM_HERE, delay1, clock_->Now());
+  RunUntilIdle();
+
+  base::TimeDelta delay2 = base::TimeDelta::FromMilliseconds(100);
+  base::TimeTicks deadline2 = clock_->Now() + delay2;
+  deadline_task_runner_->SetDeadline(FROM_HERE, delay2, clock_->Now());
+  RunUntilIdle();
+
+  EXPECT_THAT(run_times_, testing::ElementsAre(deadline1, deadline2));
+};
+
+TEST_F(DeadlineTaskRunnerTest, EarlierDeadlinesTakePrecidence) {
+  base::TimeTicks start_time = clock_->Now();
+  base::TimeDelta delay1 = base::TimeDelta::FromMilliseconds(1);
+  base::TimeDelta delay10 = base::TimeDelta::FromMilliseconds(10);
+  base::TimeDelta delay100 = base::TimeDelta::FromMilliseconds(100);
+  deadline_task_runner_->SetDeadline(FROM_HERE, delay100, clock_->Now());
+  deadline_task_runner_->SetDeadline(FROM_HERE, delay10, clock_->Now());
+  deadline_task_runner_->SetDeadline(FROM_HERE, delay1, clock_->Now());
+
+  RunUntilIdle();
+
+  EXPECT_THAT(run_times_, testing::ElementsAre(start_time + delay1));
+};
+
+TEST_F(DeadlineTaskRunnerTest, LaterDeadlinesIgnored) {
+  base::TimeTicks start_time = clock_->Now();
+  base::TimeDelta delay100 = base::TimeDelta::FromMilliseconds(100);
+  base::TimeDelta delay10000 = base::TimeDelta::FromMilliseconds(10000);
+  deadline_task_runner_->SetDeadline(FROM_HERE, delay100, clock_->Now());
+  deadline_task_runner_->SetDeadline(FROM_HERE, delay10000, clock_->Now());
+
+  RunUntilIdle();
+
+  EXPECT_THAT(run_times_, testing::ElementsAre(start_time + delay100));
+};
+
+TEST_F(DeadlineTaskRunnerTest, DeleteDeadlineTaskRunnerAfterPosting) {
+  deadline_task_runner_->SetDeadline(
+      FROM_HERE, base::TimeDelta::FromMilliseconds(10), clock_->Now());
+
+  // Deleting the pending task should cancel it.
+  deadline_task_runner_.reset(nullptr);
+  RunUntilIdle();
+
+  EXPECT_TRUE(run_times_.empty());
+};
+
+}  // namespace content