events: Clean up dispatching code for touch-events.

ui/aura/event_filter.cc

Index: ui/aura/event_filter.cc
diff --git a/ui/aura/event_filter.cc b/ui/aura/event_filter.cc
index d7f4719b468595fe4efca8f027da50c226829383..0e56533b73fab1257aa8de114e20f3d9f2c7d483 100644
--- a/ui/aura/event_filter.cc
+++ b/ui/aura/event_filter.cc
@@ -41,8 +41,25 @@ ui::EventResult EventFilter::OnScrollEvent(ui::ScrollEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
-ui::TouchStatus EventFilter::OnTouchEvent(ui::TouchEvent* event) {
-  return PreHandleTouchEvent(static_cast<Window*>(event->target()), event);
+ui::EventResult EventFilter::OnTouchEvent(ui::TouchEvent* event) {
+  ui::TouchStatus status = PreHandleTouchEvent(
+      static_cast<Window*>(event->target()), event);
+  switch (status) {
+    case ui::TOUCH_STATUS_UNKNOWN:
+      return ui::ER_UNHANDLED;
+
+    case ui::TOUCH_STATUS_START:
+    case ui::TOUCH_STATUS_CONTINUE:
+    case ui::TOUCH_STATUS_END:
+      return ui::ER_CONSUMED;
+
+    case ui::TOUCH_STATUS_QUEUED:
+    case ui::TOUCH_STATUS_QUEUED_END:
+      return ui::ER_ASYNC;
+  }
+
+  NOTREACHED();
+  return ui::ER_UNHANDLED;
 }
 
 ui::EventResult EventFilter::OnGestureEvent(ui::GestureEvent* event) {