aura: Start converting event-filters into event-handlers.

ui/aura/env.cc

Index: ui/aura/env.cc
diff --git a/ui/aura/env.cc b/ui/aura/env.cc
index e787c9957b1fb2e2ebaee34c6d552247e9566698..f562ef17b594eb774733af47856035749d4d1edb 100644
--- a/ui/aura/env.cc
+++ b/ui/aura/env.cc
@@ -97,10 +97,6 @@ void Env::SetDisplayManager(DisplayManager* display_manager) {
 #endif
 }
 
-void Env::SetEventFilter(EventFilter* event_filter) {
-  event_filter_.reset(event_filter);
-}
-
 #if !defined(OS_MACOSX)
 MessageLoop::Dispatcher* Env::GetDispatcher() {
 #if defined(USE_X11)
@@ -135,4 +131,15 @@ void Env::NotifyWindowInitialized(Window* window) {
   FOR_EACH_OBSERVER(EnvObserver, observers_, OnWindowInitialized(window));
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// Env, ui::EventTarget implementation:
+
+bool Env::CanAcceptEvents() {
+  return true;
+}
+
+ui::EventTarget* Env::GetParentTarget() {
+  return NULL;
+}
+
 }  // namespace aura