events: Move EventTarget into Event.

ui/base/events/event.h

Index: ui/base/events/event.h
diff --git a/ui/base/events/event.h b/ui/base/events/event.h
index 1b66582a730437654d672d1f1139061a92bbedb0..d2cec15ef9dc1e68c3f13006f9537db92a8f962e 100644
--- a/ui/base/events/event.h
+++ b/ui/base/events/event.h
@@ -19,11 +19,27 @@
 
 namespace ui {
 class Transform;
+class EventTarget;
 
 class UI_EXPORT Event {
  public:
   virtual ~Event();
 
+  class DispatcherApi {
+   public:
+    explicit DispatcherApi(Event* event) : event_(event) {}
+
+    void set_target(EventTarget* target) {
+      event_->target_ = target;
+    }
+
+   private:
+    DispatcherApi();
+    Event* event_;
+
+    DISALLOW_COPY_AND_ASSIGN(DispatcherApi);
+  };
+
   // For testing.
   class TestApi {
    public:
@@ -48,6 +64,8 @@ class UI_EXPORT Event {
   // events in EventFilter::PreHandleKeyEvent().
   void set_flags(int flags) { flags_ = flags; }
 
+  EventTarget* target() const { return target_; }
+
   // The following methods return true if the respective keys were pressed at
   // the time the event was created.
   bool IsShiftDown() const { return (flags_ & EF_SHIFT_DOWN) != 0; }
@@ -152,6 +170,7 @@ class UI_EXPORT Event {
   base::TimeDelta time_stamp_;
   int flags_;
   bool delete_native_event_;
+  EventTarget* target_;
 };
 
 class UI_EXPORT LocatedEvent : public Event {