Avoid two targeting phases in aura client-lib and EventProcessor.

ui/events/event_processor.cc

Index: ui/events/event_processor.cc
diff --git a/ui/events/event_processor.cc b/ui/events/event_processor.cc
index 61d2e72138a8dc51beb04f960b19197d715c750d..e44c042cc8d2da934a228c020cbcbbf304035f42 100644
--- a/ui/events/event_processor.cc
+++ b/ui/events/event_processor.cc
@@ -9,6 +9,10 @@
 
 namespace ui {
 
+EventProcessor::~EventProcessor() {
+  delete event_target_;

[sadrul, 2017/02/07 04:04:54]

This shouldn't be taking ownership of the event-target.

[riajiang, 2017/02/07 17:42:40]

Right! And no longer need this event_target_ anymore.

+}
+
 EventDispatchDetails EventProcessor::OnEventFromSource(Event* event) {
   EventTarget* root = GetRootTarget();
   CHECK(root);
@@ -26,9 +30,13 @@ EventDispatchDetails EventProcessor::OnEventFromSource(Event* event) {
   }
 
   OnEventProcessingStarted(event_to_dispatch);
-  EventTarget* target = NULL;
-  if (!event_to_dispatch->handled())
+  EventTarget* target = nullptr;
+  if (event_target_) {
+    target = event_target_;
+    event_target_ = nullptr;
+  } else if (!event_to_dispatch->handled()) {
     target = targeter->FindTargetForEvent(root, event_to_dispatch);
+  }
 
   EventDispatchDetails details;
   while (target) {