Change base::TickClock to a ref counted class.

components/copresence/handlers/audio/audio_directive_list.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 "components/copresence/handlers/audio/audio_directive_list.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/default_tick_clock.h"
@@ skipping 57 matching lines @@
       active_directives_.front().end_time < clock_->NowTicks()) {
     active_directives_.clear();
   }
 
   if (active_directives_.empty())
     return make_scoped_ptr<AudioDirective>(NULL);
 
   return make_scoped_ptr(new AudioDirective(active_directives_.front()));
 }
 
+void AudioDirectiveList::set_clock_for_testing(
+    const scoped_refptr<base::TickClock>& clock) {
+  clock_ = clock;
+}
+
+// Private methods.
+
 std::vector<AudioDirective>::iterator AudioDirectiveList::FindDirectiveByOpId(
     const std::string& op_id) {
   for (std::vector<AudioDirective>::iterator it = active_directives_.begin();
        it != active_directives_.end();
        ++it) {
     if (it->op_id == op_id)
       return it;
   }
   return active_directives_.end();
 }
 
 }  // namespace copresence