aura: Fix propagating wheel events.

ui/views/widget/native_widget_aura.cc

 // Copyright (c) 2012 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/views/widget/native_widget_aura.h"
 
 #include "base/bind.h"
 #include "base/string_util.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/aura/client/activation_change_observer.h"
@@ skipping 779 matching lines @@
                     window_->layer()->children().end(), layer));
       if (root_layer_iter > child_layer_iter)
         return false;
     }
   }
   return true;
 }
 
 bool NativeWidgetAura::OnMouseEvent(ui::MouseEvent* event) {
   DCHECK(window_->IsVisible());
-  if (event->type() == ui::ET_MOUSEWHEEL) {
-    ui::MouseWheelEvent mwe(*event);
-    return delegate_->OnMouseEvent(mwe);
-  }
+  if (event->type() == ui::ET_MOUSEWHEEL)
+    return delegate_->OnMouseEvent(*event);
 
   if (event->type() == ui::ET_SCROLL) {
     if (delegate_->OnMouseEvent(*event))
       return true;
 
     // Convert unprocessed scroll events into wheel events.
     ui::MouseWheelEvent mwe(*static_cast<ui::ScrollEvent*>(event));
     return delegate_->OnMouseEvent(mwe);
   }
   if (tooltip_manager_.get())
@@ skipping 236 matching lines @@
   return aura::Env::GetInstance()->is_mouse_button_down();
 }
 
 // static
 bool NativeWidgetPrivate::IsTouchDown() {
   return aura::Env::GetInstance()->is_touch_down();
 }
 
 }  // namespace internal
 }  // namespace views