Move throttling of background timers into the renderer scheduler

components/scheduler/base/time_domain_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/base/time_domain.h"
 
 #include "base/test/simple_test_tick_clock.h"
 #include "cc/test/ordered_simple_task_runner.h"
 #include "components/scheduler/base/task_queue_impl.h"
 #include "components/scheduler/base/task_queue_manager.h"
 #include "components/scheduler/base/task_queue_manager_delegate_for_test.h"
 #include "components/scheduler/base/test_time_source.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 using testing::_;
 using testing::Mock;
 
 namespace scheduler {
 
 class MockTimeDomain : public TimeDomain {
  public:
   MockTimeDomain()
-      : now_(base::TimeTicks() + base::TimeDelta::FromSeconds(1)) {}
+      : TimeDomain(nullptr),
+        now_(base::TimeTicks() + base::TimeDelta::FromSeconds(1)) {}
 
   using TimeDomain::NextScheduledRunTime;
   using TimeDomain::NextScheduledTaskQueue;
   using TimeDomain::ScheduleDelayedWork;
   using TimeDomain::UnregisterQueue;
   using TimeDomain::UpdateWorkQueues;
 
   // TimeSource implementation:
   LazyNow CreateLazyNow() override { return LazyNow(now_); }
 
@@ skipping 136 matching lines @@
 
   time_domain_->UpdateWorkQueues(false, nullptr);
   EXPECT_EQ(0UL, dummy_queue->IncomingQueueSizeForTest());
 
   time_domain_->SetNow(delayed_runtime);
   time_domain_->UpdateWorkQueues(false, nullptr);
   EXPECT_EQ(1UL, dummy_queue->IncomingQueueSizeForTest());
 }
 
 }  // namespace scheduler