[Media Session] Replace last updated time with TimeTicks

This is follow up from https://crrev.com/c/1706777

Replaces last updated time with base::TimeTicks.

BUG=986542

Change-Id: Icfda207848085a7b7d15c87b3fcf94c87eee3609
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1715504
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#680460}

services/media_session/public/cpp/media_position.cc

@@ -16,7 +16,7 @@ MediaPosition::MediaPosition(double playback_rate,
     : playback_rate_(playback_rate),
       duration_(duration),
       position_(position),
-      last_updated_time_(base::Time::Now()) {
+      last_updated_time_(base::TimeTicks::Now()) {
   DCHECK(duration_ >= base::TimeDelta::FromSeconds(0));
   DCHECK(position_ >= base::TimeDelta::FromSeconds(0));
   DCHECK(position_ <= duration_);
@@ -32,15 +32,15 @@ double MediaPosition::playback_rate() const {
   return playback_rate_;
 }
 
-base::Time MediaPosition::last_updated_time() const {
+base::TimeTicks MediaPosition::last_updated_time() const {
   return last_updated_time_;
 }
 
 base::TimeDelta MediaPosition::GetPosition() const {
-  return GetPositionAtTime(base::Time::Now());
+  return GetPositionAtTime(base::TimeTicks::Now());
 }
 
-base::TimeDelta MediaPosition::GetPositionAtTime(base::Time time) const {
+base::TimeDelta MediaPosition::GetPositionAtTime(base::TimeTicks time) const {
   DCHECK(time >= last_updated_time_);
 
   base::TimeDelta elapsed_time = playback_rate_ * (time - last_updated_time_);
@@ -60,7 +60,7 @@ bool MediaPosition::operator==(const MediaPosition& other) const {
   if (playback_rate_ != other.playback_rate_ || duration_ != other.duration_)
     return false;
 
-  base::Time now = base::Time::Now();
+  base::TimeTicks now = base::TimeTicks::Now();
   return GetPositionAtTime(now) == other.GetPositionAtTime(now);
 }
 

services/media_session/public/cpp/media_position.h

@@ -38,11 +38,11 @@ struct COMPONENT_EXPORT(MEDIA_SESSION_BASE_CPP) MediaPosition {
   double playback_rate() const;
 
   // Return the time the position state was last updated.
-  base::Time last_updated_time() const;
+  base::TimeTicks last_updated_time() const;
 
   // Return the updated position of the media, assuming current time is
   // |time|.
-  base::TimeDelta GetPositionAtTime(base::Time time) const;
+  base::TimeDelta GetPositionAtTime(base::TimeTicks time) const;
 
   bool operator==(const MediaPosition&) const;
   bool operator!=(const MediaPosition&) const;
@@ -76,7 +76,7 @@ struct COMPONENT_EXPORT(MEDIA_SESSION_BASE_CPP) MediaPosition {
   base::TimeDelta position_;
 
   // Last time |position_| was updated.
-  base::Time last_updated_time_;
+  base::TimeTicks last_updated_time_;
 };
 
 }  // namespace media_session

services/media_session/public/cpp/media_position_unittest.cc

@@ -15,7 +15,8 @@ TEST_F(MediaPositionTest, TestPositionUpdated) {
       1 /* playback_rate */, base::TimeDelta::FromSeconds(600) /* duration */,
       base::TimeDelta::FromSeconds(300) /* position */);
 
-  base::Time now = base::Time::Now() + base::TimeDelta::FromSeconds(100);
+  base::TimeTicks now =
+      base::TimeTicks::Now() + base::TimeDelta::FromSeconds(100);
   base::TimeDelta updated_position = media_position.GetPositionAtTime(now);
 
   EXPECT_EQ(updated_position.InSeconds(), 400);
@@ -26,7 +27,8 @@ TEST_F(MediaPositionTest, TestPositionUpdatedTwice) {
       1 /* playback_rate */, base::TimeDelta::FromSeconds(600) /* duration */,
       base::TimeDelta::FromSeconds(200) /* position */);
 
-  base::Time now = base::Time::Now() + base::TimeDelta::FromSeconds(100);
+  base::TimeTicks now =
+      base::TimeTicks::Now() + base::TimeDelta::FromSeconds(100);
   base::TimeDelta updated_position = media_position.GetPositionAtTime(now);
 
   EXPECT_EQ(updated_position.InSeconds(), 300);
@@ -42,7 +44,8 @@ TEST_F(MediaPositionTest, TestPositionUpdatedPastDuration) {
       1 /* playback_rate */, base::TimeDelta::FromSeconds(600) /* duration */,
       base::TimeDelta::FromSeconds(300) /* position */);
 
-  base::Time now = base::Time::Now() + base::TimeDelta::FromSeconds(400);
+  base::TimeTicks now =
+      base::TimeTicks::Now() + base::TimeDelta::FromSeconds(400);
   base::TimeDelta updated_position = media_position.GetPositionAtTime(now);
 
   // Verify that the position has been updated to the end of the total duration.
@@ -64,7 +67,8 @@ TEST_F(MediaPositionTest, TestNegativePosition) {
       -1 /* playback_rate */, base::TimeDelta::FromSeconds(600) /* duration */,
       base::TimeDelta::FromSeconds(300) /* position */);
 
-  base::Time now = base::Time::Now() + base::TimeDelta::FromSeconds(400);
+  base::TimeTicks now =
+      base::TimeTicks::Now() + base::TimeDelta::FromSeconds(400);
   base::TimeDelta updated_position = media_position.GetPositionAtTime(now);
 
   // Verify that the position does not go below 0.
@@ -88,7 +92,8 @@ TEST_F(MediaPositionTest, TestPositionUpdatedFasterPlayback) {
       2 /* playback_rate */, base::TimeDelta::FromSeconds(600) /* duration */,
       base::TimeDelta::FromSeconds(300) /* position */);
 
-  base::Time now = base::Time::Now() + base::TimeDelta::FromSeconds(100);
+  base::TimeTicks now =
+      base::TimeTicks::Now() + base::TimeDelta::FromSeconds(100);
   base::TimeDelta updated_position = media_position.GetPositionAtTime(now);
 
   EXPECT_EQ(updated_position.InSeconds(), 500);
@@ -99,7 +104,8 @@ TEST_F(MediaPositionTest, TestPositionUpdatedSlowerPlayback) {
       .5 /* playback_rate */, base::TimeDelta::FromSeconds(600) /* duration */,
       base::TimeDelta::FromSeconds(300) /* position */);
 
-  base::Time now = base::Time::Now() + base::TimeDelta::FromSeconds(200);
+  base::TimeTicks now =
+      base::TimeTicks::Now() + base::TimeDelta::FromSeconds(200);
   base::TimeDelta updated_position = media_position.GetPositionAtTime(now);
 
   EXPECT_EQ(updated_position.InSeconds(), 400);

services/media_session/public/cpp/media_session_mojom_traits.h

@@ -91,7 +91,7 @@ struct StructTraits<media_session::mojom::MediaPositionDataView,
     return media_position.position_;
   }
 
-  static base::Time last_updated_time(
+  static base::TimeTicks last_updated_time(
       const media_session::MediaPosition& media_position) {
     return media_position.last_updated_time_;
   }

services/media_session/public/mojom/media_session.mojom

@@ -74,7 +74,7 @@ struct MediaPosition {
   double playback_rate;
   mojo_base.mojom.TimeDelta duration;
   mojo_base.mojom.TimeDelta position;
-  mojo_base.mojom.Time last_updated_time;
+  mojo_base.mojom.TimeTicks last_updated_time;
 };
 
 // Contains state information about a MediaSession.