MacViews: Implement event monitoring for a specific window (Reland)

ui/aura/test/event_generator_delegate_aura.cc

Index: ui/aura/test/event_generator_delegate_aura.cc
diff --git a/ui/aura/test/event_generator_delegate_aura.cc b/ui/aura/test/event_generator_delegate_aura.cc
index f1158dab8fc8352ca3016790942c7ca5884dbd26..fd2ca205e17c7c1267e8f173e184730625682519 100644
--- a/ui/aura/test/event_generator_delegate_aura.cc
+++ b/ui/aura/test/event_generator_delegate_aura.cc
@@ -72,6 +72,8 @@ EventGeneratorDelegateAura::~EventGeneratorDelegateAura() {
 
 ui::EventTarget* EventGeneratorDelegateAura::GetTargetAt(
     const gfx::Point& location) {
+  // TODO(andresantoso): Add support for EventGenerator::targeting_application()
+  // if needed for Ash.
   return GetHostAt(location)->window();
 }