events: Update key-event handlers to not return EventResult.

ash/wm/system_modal_container_event_filter.cc

Index: ash/wm/system_modal_container_event_filter.cc
diff --git a/ash/wm/system_modal_container_event_filter.cc b/ash/wm/system_modal_container_event_filter.cc
index 5103d2da630219cc36062adb17c9316829568d36..da9600f6367c9ae16bdb6d1f57c3d485df7630e7 100644
--- a/ash/wm/system_modal_container_event_filter.cc
+++ b/ash/wm/system_modal_container_event_filter.cc
@@ -19,11 +19,10 @@ SystemModalContainerEventFilter::SystemModalContainerEventFilter(
 SystemModalContainerEventFilter::~SystemModalContainerEventFilter() {
 }
 
-ui::EventResult SystemModalContainerEventFilter::OnKeyEvent(
-    ui::KeyEvent* event) {
+void SystemModalContainerEventFilter::OnKeyEvent(ui::KeyEvent* event) {
   aura::Window* target = static_cast<aura::Window*>(event->target());
-  return delegate_->CanWindowReceiveEvents(target) ? ui::ER_UNHANDLED :
-                                                     ui::ER_CONSUMED;
+  if (!delegate_->CanWindowReceiveEvents(target))
+    event->StopPropagation();
 }
 
 ui::EventResult SystemModalContainerEventFilter::OnMouseEvent(