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 342 matching lines @@
 
   mock_task_runner_->RunUntilIdle();
 
   EXPECT_THAT(
       run_times,
       ElementsAre(
           base::TimeTicks() + base::TimeDelta::FromMilliseconds(1000.0),
           base::TimeTicks() + base::TimeDelta::FromMilliseconds(3000.0)));
 }
 
+TEST_F(ThrottlingHelperTest, ThrottledTasksReportRealTime) {
+  EXPECT_EQ(timer_queue_->GetTimeDomain()->Now(), clock_->NowTicks());
+
+  throttling_helper_->IncreaseThrottleRefCount(timer_queue_.get());
+  EXPECT_EQ(timer_queue_->GetTimeDomain()->Now(), clock_->NowTicks());
+
+  clock_->Advance(base::TimeDelta::FromMilliseconds(250));
+  // Make sure the throttled time domain's Now() reports the same as the
+  // underlying clock.
+  EXPECT_EQ(timer_queue_->GetTimeDomain()->Now(), 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.
   EXPECT_TRUE(timer_queue_->IsQueueEnabled());
 }
@@ skipping 61 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