Change base::TickClock to a ref counted class.

extensions/browser/api/cast_channel/logger.cc

Index: extensions/browser/api/cast_channel/logger.cc
diff --git a/extensions/browser/api/cast_channel/logger.cc b/extensions/browser/api/cast_channel/logger.cc
index bddf53971c24515792cbe689486390e8a7905159..619eb477e75667a03cfbe15e4436b173d7e210a9 100644
--- a/extensions/browser/api/cast_channel/logger.cc
+++ b/extensions/browser/api/cast_channel/logger.cc
@@ -127,10 +127,10 @@ Logger::AggregatedSocketEventLog::AggregatedSocketEventLog() {
 Logger::AggregatedSocketEventLog::~AggregatedSocketEventLog() {
 }
 
-Logger::Logger(scoped_ptr<base::TickClock> clock,
+Logger::Logger(const scoped_refptr<base::TickClock>& clock,
                base::TimeTicks unix_epoch_time_ticks)
-    : clock_(clock.Pass()), unix_epoch_time_ticks_(unix_epoch_time_ticks) {
-  DCHECK(clock_);
+    : clock_(clock), unix_epoch_time_ticks_(unix_epoch_time_ticks) {
+  DCHECK(clock_.get() != NULL);
 
   // Logger may not be necessarily be created on the IO thread, but logging
   // happens exclusively there.