Laser tool blocks events from propagating.

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index 3b9d420930df29af3c0914830b027aa50e83fb4d..91b94c6bf41938de25c35592c013f4c6882c1978 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -87,6 +87,7 @@ class FirstRunHelper;
 class GPUSupport;
 class HighContrastController;
 class ImmersiveHandlerFactoryAsh;
+class LaserPointerController;
 class LinkHandlerModelFactory;
 class LocaleNotificationController;
 class LockStateController;
@@ -313,6 +314,10 @@ class ASH_EXPORT Shell : public SystemModalContainerEventFilterDelegate,
     return high_contrast_controller_.get();
   }
 
+  LaserPointerController* laser_pointer_controller() {
+    return laser_pointer_controller_.get();
+  }
+
   MagnificationController* magnification_controller() {
     return magnification_controller_.get();
   }
@@ -497,6 +502,7 @@ class ASH_EXPORT Shell : public SystemModalContainerEventFilterDelegate,
   std::unique_ptr<VideoDetector> video_detector_;
   std::unique_ptr<WindowTreeHostManager> window_tree_host_manager_;
   std::unique_ptr<HighContrastController> high_contrast_controller_;
+  std::unique_ptr<LaserPointerController> laser_pointer_controller_;
   std::unique_ptr<MagnificationController> magnification_controller_;
   std::unique_ptr<PartialMagnificationController>
       partial_magnification_controller_;