Fix mouse wheel events processing.

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/location.h"
 #include "base/memory/ptr_util.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 902 matching lines @@
     return;
 
   delegate_->OnKeyEvent(event);
 }
 
 void NativeWidgetAura::OnMouseEvent(ui::MouseEvent* event) {
   DCHECK(window_);
   DCHECK(window_->IsVisible());
   if (event->type() == ui::ET_MOUSEWHEEL) {
     delegate_->OnMouseEvent(event);
-    if (event->handled())
-      return;
+    return;
   }
 
   if (tooltip_manager_.get())
     tooltip_manager_->UpdateTooltip();
   TooltipManagerAura::UpdateTooltipManagerForCapture(GetWidget());
   delegate_->OnMouseEvent(event);
 }
 
 void NativeWidgetAura::OnScrollEvent(ui::ScrollEvent* event) {
   delegate_->OnScrollEvent(event);
@@ skipping 280 matching lines @@
     gfx::NativeView native_view) {
   aura::client::CaptureClient* capture_client =
       aura::client::GetCaptureClient(native_view->GetRootWindow());
   if (!capture_client)
     return nullptr;
   return capture_client->GetGlobalCaptureWindow();
 }
 
 }  // namespace internal
 }  // namespace views