Refactored static_cast'ing of events to use the AsXXXEvent() methods.

ui/events/ozone/evdev/input_injector_evdev_unittest.cc

Index: ui/events/ozone/evdev/input_injector_evdev_unittest.cc
diff --git a/ui/events/ozone/evdev/input_injector_evdev_unittest.cc b/ui/events/ozone/evdev/input_injector_evdev_unittest.cc
index fe07e328cf6603320a18d86510c2076f68629b17..d373f6534cc7b2eaf672e6c5ac0810891874f3d3 100644
--- a/ui/events/ozone/evdev/input_injector_evdev_unittest.cc
+++ b/ui/events/ozone/evdev/input_injector_evdev_unittest.cc
@@ -32,9 +32,9 @@ class EventObserver {
   void OnEvent(Event* event) {
     if (event->IsMouseEvent()) {
       if (event->type() == ET_MOUSEWHEEL) {
-        OnMouseWheelEvent(static_cast<MouseWheelEvent*>(event));
+        OnMouseWheelEvent(event->AsMouseWheelEvent());
       } else {
-        OnMouseEvent(static_cast<MouseEvent*>(event));
+        OnMouseEvent(event->AsMouseEvent());
       }
     }
   }