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..122fe654c2815dfcd02037764a7b06707f316769 100644
--- a/ash/laser/laser_pointer_points.cc
+++ b/ash/laser/laser_pointer_points.cc
@@ -15,10 +15,25 @@ LaserPointerPoints::LaserPointerPoints(base::TimeDelta life_duration)
 LaserPointerPoints::~LaserPointerPoints() {}
 
 void LaserPointerPoints::AddPoint(const gfx::Point& point) {
+  base::Time current_time = base::Time::Now();
+  // If the collection is empty, set the latest time to the time of the first
+  // added point.
+  if (IsEmpty())
+    collection_latest_time_ = current_time;

[jdufault, 2016/09/23 23:59:19]

We should always be updating collection_latest_time_, otherwise the logic in
MoveForwardInTime will use a stale value.

[sammiequon, 2016/09/26 19:30:38]

Done.

   LaserPoint new_point;
   new_point.location = point;
-  new_point.creation_time = base::Time::Now();
+  new_point.creation_time = current_time;
   points_.push_back(new_point);
+  MoveForwardInTime(current_time);
+}
+
+void LaserPointerPoints::MoveForwardInTime() {
+  collection_latest_time_ = base::Time::Now();

[jdufault, 2016/09/23 23:59:19]

Call MoveFowardInTime(base::Time::Now())

[sammiequon, 2016/09/26 19:30:38]

Done.

+  ClearOldPoints();
+}
+
+void LaserPointerPoints::MoveForwardInTime(const base::Time& new_latest_time) {

[jdufault, 2016/09/23 23:59:19]

Rename one of the MoveForwardInTime methods so they are not overloaded.

[sammiequon, 2016/09/26 19:30:38]

Done.

+  collection_latest_time_ = new_latest_time;
   ClearOldPoints();
 }
 
@@ -49,6 +64,14 @@ LaserPointerPoints::LaserPoint LaserPointerPoints::GetNewest() const {
   return points_.back();
 }
 
+base::Time LaserPointerPoints::GetCollectionLatestTime() const {
+  return collection_latest_time_;
+}
+
+base::Time LaserPointerPoints::GetCollectionEarliestTime() const {
+  return collection_latest_time_ - life_duration_;
+}
+
 bool LaserPointerPoints::IsEmpty() const {
   return points_.empty();
 }
@@ -63,10 +86,12 @@ LaserPointerPoints::laser_points() {
 }
 
 void LaserPointerPoints::ClearOldPoints() {
-  DCHECK(!IsEmpty());
+  if (IsEmpty())

[jdufault, 2016/09/23 23:59:19]

Why do we need this if?

[sammiequon, 2016/09/26 19:30:38]

Done.

+    return;
+
   auto first_alive_point =
       std::find_if(points_.begin(), points_.end(), [this](LaserPoint& p) {
-        return GetNewest().creation_time - p.creation_time < life_duration_;
+        return collection_latest_time_ - p.creation_time < life_duration_;
       });
   points_.erase(points_.begin(), first_alive_point);
 }