Redesign the copresence audio handlers.

components/copresence/handlers/audio/audio_directive_list.cc

Index: components/copresence/handlers/audio/audio_directive_list.cc
diff --git a/components/copresence/handlers/audio/audio_directive_list.cc b/components/copresence/handlers/audio/audio_directive_list.cc
index 2dc505bb8af50305cefe976f51a7de636dcb6044..8b9b76ec21d1945b9955ea17bba27e41e8b892c1 100644
--- a/components/copresence/handlers/audio/audio_directive_list.cc
+++ b/components/copresence/handlers/audio/audio_directive_list.cc
@@ -7,6 +7,8 @@
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/time/default_tick_clock.h"
+#include "base/time/tick_clock.h"
 #include "base/time/time.h"
 
 namespace copresence {
@@ -16,11 +18,12 @@ namespace copresence {
 AudioDirective::AudioDirective() {
 }
 
-AudioDirective::AudioDirective(const std::string& op_id, base::Time end_time)
+AudioDirective::AudioDirective(const std::string& op_id,
+                               base::TimeTicks end_time)
     : op_id(op_id), end_time(end_time) {
 }
 
-AudioDirectiveList::AudioDirectiveList() {
+AudioDirectiveList::AudioDirectiveList() : clock_(new base::DefaultTickClock) {
 }
 
 AudioDirectiveList::~AudioDirectiveList() {
@@ -28,7 +31,7 @@ AudioDirectiveList::~AudioDirectiveList() {
 
 void AudioDirectiveList::AddDirective(const std::string& op_id,
                                       base::TimeDelta ttl) {
-  base::Time end_time = base::Time::Now() + ttl;
+  base::TimeTicks end_time = clock_->NowTicks() + ttl;
 
   // In case this op is already in the list, update it instead of adding
   // it again.
@@ -62,7 +65,7 @@ scoped_ptr<AudioDirective> AudioDirectiveList::GetActiveDirective() {
   // has passed, means all our previous instructions have expired too, hence
   // clear the list.
   if (!active_directives_.empty() &&
-      active_directives_.front().end_time < base::Time::Now()) {
+      active_directives_.front().end_time < clock_->NowTicks()) {
     active_directives_.clear();
   }