Add POINTER_WHEEL_CHANGED event to mojo.

services/ui/public/cpp/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 "services/ui/public/cpp/window_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 985 matching lines @@
   }
 
   std::unique_ptr<base::Callback<void(mojom::EventResult)>> ack_callback(
       new base::Callback<void(mojom::EventResult)>(
           base::Bind(&mojom::WindowTree::OnWindowInputEventAck,
                      base::Unretained(tree_), 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()) {
-    window->input_event_handler_->OnWindowInputEvent(
-        window, ui::MouseEvent(*event->AsPointerEvent()), &ack_callback);
+    if (event->type() == ui::ET_POINTER_WHEEL_CHANGED) {
+      window->input_event_handler_->OnWindowInputEvent(
+          window, ui::MouseWheelEvent(*event->AsPointerEvent()), &ack_callback);
+    } else {
+      window->input_event_handler_->OnWindowInputEvent(
+          window, ui::MouseEvent(*event->AsPointerEvent()), &ack_callback);
+    }
   } else if (event->IsTouchPointerEvent()) {
     window->input_event_handler_->OnWindowInputEvent(
         window, ui::TouchEvent(*event->AsPointerEvent()), &ack_callback);
   } else {
     window->input_event_handler_->OnWindowInputEvent(window, *event.get(),
                                                      &ack_callback);
   }
 
   // The handler did not take ownership of the callback, so we send the ack,
   // marking the event as not consumed.
@@ skipping 243 matching lines @@
     Window* window,
     const gfx::Vector2d& offset,
     const gfx::Insets& hit_area) {
   if (window_manager_internal_client_) {
     window_manager_internal_client_->SetUnderlaySurfaceOffsetAndExtendedHitArea(
         server_id(window), offset.x(), offset.y(), hit_area);
   }
 }
 
 }  // namespace ui