Add MockOneShotTimer and MockRepeatingTimer

MockOneShotTimer and MockRepeatingTimer are subclasses of OneShotTimer
and RepeatingTimer respectively, that are intended to replace most of
MockTimer.

As MockTimer is not a OneShotTimer nor RepeatingTimer, when we want to
use MockTimer for other timers, we had to use the generic Timer to hold
a timer instance, that loses the timer traits from its type.

Change-Id: Iea4a469708be2b89d4feb228460d78ab2a2f96d1
Reviewed-on: https://chromium-review.googlesource.com/1095195
Commit-Queue: Taiju Tsuiki <tzik@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568371}

base/timer/mock_timer.cc

@@ -8,6 +8,21 @@
 
 namespace base {
 
+namespace {
+
+void FlushPendingTasks(TestSimpleTaskRunner* task_runner) {
+  // Do not use TestSimpleTaskRunner::RunPendingTasks() here. As RunPendingTasks
+  // overrides ThreadTaskRunnerHandle when it runs tasks, tasks posted by timer
+  // tasks to TTRH go to |test_task_runner_|, though they should be posted to
+  // the original task runner.
+  // Do not use TestSimpleTaskRunner::RunPendingTasks(), as its overridden
+  // ThreadTaskRunnerHandle causes unexpected side effects.
+  for (TestPendingTask& task : task_runner->TakePendingTasks())
+    std::move(task.task).Run();
+}
+
+}  // namespace
+
 MockTimer::MockTimer(bool retain_user_task, bool is_repeating)
     : Timer(retain_user_task, is_repeating, &clock_),
       test_task_runner_(MakeRefCounted<TestSimpleTaskRunner>()) {
@@ -23,13 +38,45 @@ void MockTimer::SetTaskRunner(scoped_refptr<SequencedTaskRunner> task_runner) {
 void MockTimer::Fire() {
   DCHECK(IsRunning());
   clock_.Advance(std::max(TimeDelta(), desired_run_time() - clock_.NowTicks()));
+  FlushPendingTasks(test_task_runner_.get());
+}
 
-  // Do not use TestSimpleTaskRunner::RunPendingTasks() here. As RunPendingTasks
-  // overrides ThreadTaskRunnerHandle when it runs tasks, tasks posted by timer
-  // tasks to TTRH go to |test_task_runner_|, though they should be posted to
-  // the original task runner.
-  for (TestPendingTask& task : test_task_runner_->TakePendingTasks())
-    std::move(task.task).Run();
+MockOneShotTimer::MockOneShotTimer()
+    : OneShotTimer(&clock_),
+      test_task_runner_(MakeRefCounted<TestSimpleTaskRunner>()) {
+  OneShotTimer::SetTaskRunner(test_task_runner_);
+}
+
+MockOneShotTimer::~MockOneShotTimer() = default;
+
+void MockOneShotTimer::SetTaskRunner(
+    scoped_refptr<SequencedTaskRunner> task_runner) {
+  NOTREACHED() << "MockOneShotTimer doesn't support SetTaskRunner().";
+}
+
+void MockOneShotTimer::Fire() {
+  DCHECK(IsRunning());
+  clock_.Advance(std::max(TimeDelta(), desired_run_time() - clock_.NowTicks()));
+  FlushPendingTasks(test_task_runner_.get());
+}
+
+MockRepeatingTimer::MockRepeatingTimer()
+    : RepeatingTimer(&clock_),
+      test_task_runner_(MakeRefCounted<TestSimpleTaskRunner>()) {
+  RepeatingTimer::SetTaskRunner(test_task_runner_);
+}
+
+MockRepeatingTimer::~MockRepeatingTimer() = default;
+
+void MockRepeatingTimer::SetTaskRunner(
+    scoped_refptr<SequencedTaskRunner> task_runner) {
+  NOTREACHED() << "MockRepeatingTimer doesn't support SetTaskRunner().";
+}
+
+void MockRepeatingTimer::Fire() {
+  DCHECK(IsRunning());
+  clock_.Advance(std::max(TimeDelta(), desired_run_time() - clock_.NowTicks()));
+  FlushPendingTasks(test_task_runner_.get());
 }
 
 }  // namespace base

base/timer/mock_timer.h

@@ -33,6 +33,42 @@ class MockTimer : public Timer {
   scoped_refptr<TestSimpleTaskRunner> test_task_runner_;
 };
 
+// See MockTimer's comment. Prefer using ScopedTaskEnvironment::MOCK_TIME.
+class MockOneShotTimer : public OneShotTimer {
+ public:
+  MockOneShotTimer();
+  ~MockOneShotTimer() override;
+
+  // Testing method.
+  void Fire();
+
+ private:
+  // Timer implementation.
+  // MockOneShotTimer doesn't support SetTaskRunner. Do not use this.
+  void SetTaskRunner(scoped_refptr<SequencedTaskRunner> task_runner) override;
+
+  SimpleTestTickClock clock_;
+  scoped_refptr<TestSimpleTaskRunner> test_task_runner_;
+};
+
+// See MockTimer's comment. Prefer using ScopedTaskEnvironment::MOCK_TIME.
+class MockRepeatingTimer : public RepeatingTimer {
+ public:
+  MockRepeatingTimer();
+  ~MockRepeatingTimer() override;
+
+  // Testing method.
+  void Fire();
+
+ private:
+  // Timer implementation.
+  // MockRepeatingTimer doesn't support SetTaskRunner. Do not use this.
+  void SetTaskRunner(scoped_refptr<SequencedTaskRunner> task_runner) override;
+
+  SimpleTestTickClock clock_;
+  scoped_refptr<TestSimpleTaskRunner> test_task_runner_;
+};
+
 }  // namespace base
 
 #endif  // BASE_TIMER_MOCK_TIMER_H_