Change base::TickClock to a ref counted class.

media/base/wall_clock_time_source.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 "media/base/wall_clock_time_source.h"
 
 #include "base/logging.h"
 #include "base/time/default_tick_clock.h"
 
 namespace media {
@@ skipping 47 matching lines @@
 base::TimeDelta WallClockTimeSource::CurrentMediaTime() {
   base::AutoLock auto_lock(lock_);
   return CurrentMediaTime_Locked();
 }
 
 base::TimeDelta WallClockTimeSource::CurrentMediaTimeForSyncingVideo() {
   return CurrentMediaTime();
 }
 
 void WallClockTimeSource::SetTickClockForTesting(
-    scoped_ptr<base::TickClock> tick_clock) {
-  tick_clock_.swap(tick_clock);
+    const scoped_refptr<base::TickClock>& tick_clock) {
+  tick_clock_ = tick_clock;
 }
 
 base::TimeDelta WallClockTimeSource::CurrentMediaTime_Locked() {
   lock_.AssertAcquired();
   if (!ticking_)
     return base_time_;
 
   base::TimeTicks now = tick_clock_->NowTicks();
   return base_time_ +
          base::TimeDelta::FromMicroseconds(
              (now - reference_wall_ticks_).InMicroseconds() * playback_rate_);
 }
 
 }  // namespace media