ash: Use floating point precision for laser pointer.

ash/laser/laser_pointer_view.h

Index: ash/laser/laser_pointer_view.h
diff --git a/ash/laser/laser_pointer_view.h b/ash/laser/laser_pointer_view.h
index 13abf867c2afde9c69dbc7f2d197a40a7232ee8a..55ff8344ef0574142a20c5b05a7b3a4b5d4cee96 100644
--- a/ash/laser/laser_pointer_view.h
+++ b/ash/laser/laser_pointer_view.h
@@ -27,7 +27,7 @@ class Window;
 
 namespace gfx {
 class GpuMemoryBuffer;
-class Point;
+class PointF;
 }
 
 namespace views {
@@ -47,7 +47,7 @@ class LaserPointerView : public views::View,
   LaserPointerView(base::TimeDelta life_duration, aura::Window* root_window);
   ~LaserPointerView() override;
 
-  void AddNewPoint(const gfx::Point& new_point);
+  void AddNewPoint(const gfx::PointF& new_point);
   void UpdateTime();
   void Stop();