Provision to start base::SimpleTestTickClock at initial ticks

components/scheduler/child/idle_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/child/idle_helper.h"
 
 #include "base/callback.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "cc/test/ordered_simple_task_runner.h"
 #include "components/scheduler/child/nestable_task_runner_for_test.h"
@@ skipping 149 matching lines @@
   MOCK_METHOD0(IsNotQuiescent, void());
   MOCK_METHOD0(OnIdlePeriodStarted, void());
   MOCK_METHOD0(OnIdlePeriodEnded, void());
 };
 
 class BaseIdleHelperTest : public testing::Test {
  public:
   BaseIdleHelperTest(
       base::MessageLoop* message_loop,
       base::TimeDelta required_quiescence_duration_before_long_idle_period)
-      : clock_(new base::SimpleTestTickClock()),
+      : clock_(new base::SimpleTestTickClock(
+            base::TimeTicks() + base::TimeDelta::FromMicroseconds(1))),
         mock_task_runner_(
             message_loop
                 ? nullptr
                 : new cc::OrderedSimpleTaskRunner(clock_.get(), false)),
         message_loop_(message_loop),
         nestable_task_runner_(
             CreateNestableSingleThreadTaskRunner(message_loop,
                                                  mock_task_runner_)),
         scheduler_helper_(
             new SchedulerHelper(nestable_task_runner_,
                                 "test.idle",
                                 TRACE_DISABLED_BY_DEFAULT("test.idle"),
                                 TRACE_DISABLED_BY_DEFAULT("test.idle.debug"),
                                 SchedulerHelper::TASK_QUEUE_COUNT + 1)),
         idle_helper_(new IdleHelperForTest(
             scheduler_helper_.get(),
             required_quiescence_duration_before_long_idle_period)),
         default_task_runner_(scheduler_helper_->DefaultTaskRunner()),
         idle_task_runner_(idle_helper_->IdleTaskRunner()) {
-    clock_->Advance(base::TimeDelta::FromMicroseconds(5000));
     scheduler_helper_->SetTimeSourceForTesting(
         make_scoped_ptr(new TestTimeSource(clock_.get())));
     scheduler_helper_->GetTaskQueueManagerForTesting()->SetTimeSourceForTesting(
         make_scoped_ptr(new TestTimeSource(clock_.get())));
   }
 
   ~BaseIdleHelperTest() override {}
 
   void SetUp() override {
     EXPECT_CALL(*idle_helper_, OnIdlePeriodStarted()).Times(AnyNumber());
@@ skipping 937 matching lines @@
   EXPECT_EQ(0, run_count);
 
   default_task_runner_->PostDelayedTask(FROM_HERE, base::Bind(&NullTask),
                                         more_than_min_deadline_duration);
   idle_helper_->EnableLongIdlePeriod();
   RunUntilIdle();
   EXPECT_EQ(1, run_count);
 }
 
 }  // namespace scheduler