Fix a bug that could occasionaly cause setInterval to stop

components/scheduler/renderer/throttling_helper_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/throttling_helper.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 312 matching lines @@
 
   EXPECT_EQ(2u, task_count);  // There are two since the cancelled task runs in
   // the same DoWork batch.
 
   EXPECT_THAT(
       run_times,
       ElementsAre(base::TimeTicks() + base::TimeDelta::FromSeconds(6),
                   base::TimeTicks() + base::TimeDelta::FromSeconds(16)));
 }
 
-TEST_F(ThrottlingHelperTest, TaskDelayIsBasedOnRealTime) {
-  std::vector<base::TimeTicks> run_times;
+TEST_F(ThrottlingHelperTest, ThrottledTasksReportRealTimeToBlink) {
+  clock_->Advance(base::TimeDelta::FromSeconds(1));
+
+  EXPECT_EQ(timer_queue_->GetTimeDomain()->BlinkNow(), clock_->NowTicks());
 
   throttling_helper_->IncreaseThrottleRefCount(timer_queue_.get());
+  // Note the throttled time domain's view of time is usally in the past.
+  EXPECT_LT(timer_queue_->GetTimeDomain()->Now(), clock_->NowTicks());
+  // But we report the current real time to blink.
+  EXPECT_EQ(timer_queue_->GetTimeDomain()->BlinkNow(), clock_->NowTicks());
 
-  // Post an initial task that should run at the first aligned time period.
-  timer_queue_->PostDelayedTask(FROM_HERE,
-                                base::Bind(&TestTask, &run_times, clock_.get()),
-                                base::TimeDelta::FromMilliseconds(900.0));
-
-  mock_task_runner_->RunUntilIdle();
-
-  // Advance realtime.
+  // Advance realtime, and make sure BlinkNow advances too.
   clock_->Advance(base::TimeDelta::FromMilliseconds(250));
-
-  // Post a task that due to real time + delay must run in the third aligned
-  // time period.
-  timer_queue_->PostDelayedTask(FROM_HERE,
-                                base::Bind(&TestTask, &run_times, clock_.get()),
-                                base::TimeDelta::FromMilliseconds(900.0));
-
-  mock_task_runner_->RunUntilIdle();
-
-  EXPECT_THAT(
-      run_times,
-      ElementsAre(
-          base::TimeTicks() + base::TimeDelta::FromMilliseconds(1000.0),
-          base::TimeTicks() + base::TimeDelta::FromMilliseconds(3000.0)));
+  EXPECT_LT(timer_queue_->GetTimeDomain()->Now(), clock_->NowTicks());
+  EXPECT_EQ(timer_queue_->GetTimeDomain()->BlinkNow(), clock_->NowTicks());
 }
 
 TEST_F(ThrottlingHelperTest, TaskQueueDisabledTillPump) {
   timer_queue_->PostTask(FROM_HERE, base::Bind(&NopTask));
 
   EXPECT_TRUE(timer_queue_->IsQueueEnabled());
   throttling_helper_->IncreaseThrottleRefCount(timer_queue_.get());
   EXPECT_FALSE(timer_queue_->IsQueueEnabled());
 
   mock_task_runner_->RunUntilIdle();  // Wait until the pump.
@@ skipping 63 matching lines @@
   EXPECT_TRUE(timer_queue_->IsQueueEnabled());
   throttling_helper_->IncreaseThrottleRefCount(timer_queue_.get());
   throttling_helper_->IncreaseThrottleRefCount(timer_queue_.get());
   EXPECT_FALSE(timer_queue_->IsQueueEnabled());
   throttling_helper_->DecreaseThrottleRefCount(timer_queue_.get());
   throttling_helper_->DecreaseThrottleRefCount(timer_queue_.get());
   EXPECT_TRUE(timer_queue_->IsQueueEnabled());
 }
 
 }  // namespace scheduler