Change base::TickClock to a ref counted class.

ash/system/chromeos/session/logout_confirmation_controller_unittest.cc

 // Copyright 2014 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 "ash/system/chromeos/session/logout_confirmation_controller.h"
 
 #include <queue>
 #include <utility>
 #include <vector>
 
@@ skipping 49 matching lines @@
                       TemporalOrder> tasks_;
 
   DISALLOW_COPY_AND_ASSIGN(MockTimeSingleThreadTaskRunner);
 };
 
 // A base::TickClock that uses a MockTimeSingleThreadTaskRunner as the source of
 // the current time.
 class MockClock : public base::TickClock {
  public:
   explicit MockClock(scoped_refptr<MockTimeSingleThreadTaskRunner> task_runner);
-  virtual ~MockClock();
-
   // base::TickClock:
   virtual base::TimeTicks NowTicks() override;
 
  private:
+  virtual ~MockClock();
+
   scoped_refptr<MockTimeSingleThreadTaskRunner> task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(MockClock);
 };
 
 
 MockTimeSingleThreadTaskRunner::MockTimeSingleThreadTaskRunner() {
 }
 
 bool MockTimeSingleThreadTaskRunner::RunsTasksOnCurrentThread() const {
@@ skipping 195 matching lines @@
   controller_.ConfirmLogout(
       runner_->GetCurrentTime() + base::TimeDelta::FromSeconds(10));
   EXPECT_FALSE(log_out_called_);
   runner_->FastForwardBy(base::TimeDelta::FromSeconds(9));
   EXPECT_FALSE(log_out_called_);
   runner_->FastForwardBy(base::TimeDelta::FromSeconds(2));
   EXPECT_TRUE(log_out_called_);
 }
 
 }  // namespace ash