Update PointerEvent handled state correctly in OnWindowInputEvent.

ui/aura/mus/window_tree_client.cc

 // 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.
 
 #include "ui/aura/mus/window_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 1220 matching lines @@
 
   // TODO: use |display_id| to find host and send there.
   if (!window || !window->GetWindow()->GetHost()) {
     tree_->OnWindowInputEventAck(event_id, ui::mojom::EventResult::UNHANDLED);
     return;
   }
 
   EventAckHandler ack_handler(CreateEventResultCallback(event_id));
   // TODO(moshayedi): crbug.com/617222. No need to convert to ui::MouseEvent or
   // ui::TouchEvent once we have proper support for pointer events.
   if (event->IsMousePointerEvent()) {

[sky, 2017/03/31 17:41:24]

In hopes of reducing copy/paste, WDYT of a MapEvent functions that takes a const
ui::Event& and returns std::unique_ptr<ui::Event> ? MapEvent has the logic of
creating and return the right Event subclass. That way the code here comes:

std::unique_ptr<ui::Event> mapped_event = MapEvent(event.get());
DispatchEventToTarget(mapped_event.get(), window);
ack_handler.set_handled(mapped_event->handled());
?

[riajiang, 2017/03/31 18:33:04]

Yea that's cleaner! Done.

     if (event->type() == ui::ET_POINTER_WHEEL_CHANGED) {
       ui::MouseWheelEvent mapped_event(*event->AsPointerEvent());
       DispatchEventToTarget(&mapped_event, window);
+      ack_handler.set_handled(mapped_event.handled());
     } else {
       ui::MouseEvent mapped_event(*event->AsPointerEvent());
       DispatchEventToTarget(&mapped_event, window);
+      ack_handler.set_handled(mapped_event.handled());
     }
   } else if (event->IsTouchPointerEvent()) {
     ui::TouchEvent mapped_event(*event->AsPointerEvent());
     DispatchEventToTarget(&mapped_event, window);
+    ack_handler.set_handled(mapped_event.handled());
   } else {
     DispatchEventToTarget(event.get(), window);
+    ack_handler.set_handled(event->handled());
   }
-  ack_handler.set_handled(event->handled());
 }
 
 void WindowTreeClient::OnPointerEventObserved(std::unique_ptr<ui::Event> event,
                                               uint32_t window_id,
                                               int64_t display_id) {
   DCHECK(event);
   DCHECK(event->IsPointerEvent());
   if (!has_pointer_watcher_)
     return;
 
@@ skipping 682 matching lines @@
   return ScheduleInFlightChange(base::MakeUnique<InFlightCaptureChange>(
       this, capture_synchronizer_.get(), window));
 }
 
 uint32_t WindowTreeClient::CreateChangeIdForFocus(WindowMus* window) {
   return ScheduleInFlightChange(base::MakeUnique<InFlightFocusChange>(
       this, focus_synchronizer_.get(), window));
 }
 
 }  // namespace aura