cros: Laser pointer fades out on release, do not cover palette.

ash/laser/laser_pointer_points.cc

Index: ash/laser/laser_pointer_points.cc
diff --git a/ash/laser/laser_pointer_points.cc b/ash/laser/laser_pointer_points.cc
index 8f2176ed8dbdfe42a5a5d5d2e78c3425e5797c5b..0d6c7f843e9783b941c5a9ceb3515eb319741dce 100644
--- a/ash/laser/laser_pointer_points.cc
+++ b/ash/laser/laser_pointer_points.cc
@@ -15,11 +15,30 @@ LaserPointerPoints::LaserPointerPoints(base::TimeDelta life_duration)
 LaserPointerPoints::~LaserPointerPoints() {}
 
 void LaserPointerPoints::AddPoint(const gfx::Point& point) {
+  base::Time current_time = base::Time::Now();

[jdufault, 2016/10/05 18:08:51]

Remove this helper variable.

[sammiequon, 2016/10/05 21:15:22]

Done.

   LaserPoint new_point;
   new_point.location = point;
-  new_point.creation_time = base::Time::Now();
+  new_point.age = 0.0;
+  MoveForwardToTime(current_time);
   points_.push_back(new_point);
+}
+
+void LaserPointerPoints::MoveForwardToCurrentTime() {
+  MoveForwardToTime(base::Time::Now());
+}
+
+void LaserPointerPoints::MoveForwardToTime(const base::Time& new_latest_time) {
+  if (collection_latest_time_.is_null())
+    collection_latest_time_ = new_latest_time;
+
+  // Update the ages of the points based on the change in new latest time.
+  auto delta = new_latest_time - collection_latest_time_;

[jdufault, 2016/10/05 18:08:51]

Specify type

[sammiequon, 2016/10/05 21:15:22]

Done.

+  double lifespan_change =
+      delta.InMillisecondsF() / life_duration_.InMillisecondsF();
+  for (auto& point : points_)

[jdufault, 2016/10/05 18:08:51]

Specify type

[sammiequon, 2016/10/05 21:15:22]

Done.

+    point.age += lifespan_change;
   ClearOldPoints();
+  collection_latest_time_ = new_latest_time;
 }
 
 void LaserPointerPoints::Clear() {
@@ -63,12 +82,9 @@ LaserPointerPoints::laser_points() {
 }
 
 void LaserPointerPoints::ClearOldPoints() {
-  DCHECK(!IsEmpty());
   auto first_alive_point =
-      std::find_if(points_.begin(), points_.end(), [this](LaserPoint& p) {
-        return GetNewest().creation_time - p.creation_time < life_duration_;
-      });
+      std::find_if(points_.begin(), points_.end(),
+                   [](LaserPoint& p) { return p.age < 1.0; });
   points_.erase(points_.begin(), first_alive_point);
 }
-
 }  // namespace ash