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

ui/aura/window_event_dispatcher.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_AURA_WINDOW_EVENT_DISPATCHER_H_
 #define UI_AURA_WINDOW_EVENT_DISPATCHER_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 42 matching lines @@
                                           public client::CaptureDelegate,
                                           public WindowObserver,
                                           public EnvObserver {
  public:
   explicit WindowEventDispatcher(WindowTreeHost* host);
   ~WindowEventDispatcher() override;
 
   Window* mouse_pressed_handler() { return mouse_pressed_handler_; }
   Window* mouse_moved_handler() { return mouse_moved_handler_; }
 
+  // Overridden from ui::EventProcessor:
+  ui::EventTargeter* GetDefaultEventTargeter() override;
+
   // Repost event for re-processing. Used when exiting context menus.
   // We support the ET_MOUSE_PRESSED, ET_TOUCH_PRESSED and ET_GESTURE_TAP_DOWN
   // event types (although the latter is currently a no-op).
   void RepostEvent(const ui::LocatedEvent* event);
 
   // Invoked when the mouse events get enabled or disabled.
   void OnMouseEventsEnableStateChanged(bool enabled);
 
   void DispatchCancelModeEvent();
 
@@ skipping 93 matching lines @@
 
   bool is_dispatched_held_event(const ui::Event& event) const;
 
   // Overridden from aura::client::CaptureDelegate:
   void UpdateCapture(Window* old_capture, Window* new_capture) override;
   void OnOtherRootGotCapture() override;
   void SetNativeCapture() override;
   void ReleaseNativeCapture() override;
 
   // Overridden from ui::EventProcessor:
-  ui::EventTarget* GetRootTarget() override;
+  ui::EventTarget* GetRootForEvent(ui::Event* event) override;
   void OnEventProcessingStarted(ui::Event* event) override;
   void OnEventProcessingFinished(ui::Event* event) override;
 
   // Overridden from ui::EventDispatcherDelegate.
   bool CanDispatchToTarget(ui::EventTarget* target) override;
   ui::EventDispatchDetails PreDispatchEvent(ui::EventTarget* target,
                                             ui::Event* event) override;
   ui::EventDispatchDetails PostDispatchEvent(ui::EventTarget* target,
                                              const ui::Event& event) override;
 
@@ skipping 68 matching lines @@
 
   // Set when dispatching a held event.
   ui::LocatedEvent* dispatching_held_event_;
 
   ScopedObserver<aura::Window, aura::WindowObserver> observer_manager_;
 
   std::unique_ptr<EnvInputStateController> env_controller_;
 
   std::unique_ptr<MusMouseLocationUpdater> mus_mouse_location_updater_;
 
+  // The default EventTargeter for WindowEventDispatcher generated events.
+  std::unique_ptr<ui::EventTargeter> event_targeter_;
+
   // Used to schedule reposting an event.
   base::WeakPtrFactory<WindowEventDispatcher> repost_event_factory_;
 
   // Used to schedule DispatchHeldEvents() when |move_hold_count_| goes to 0.
   base::WeakPtrFactory<WindowEventDispatcher> held_event_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowEventDispatcher);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_WINDOW_EVENT_DISPATCHER_H_