views: Target the synthetic wheel events to the view under the mouse cursor.

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_client.h"
@@ skipping 781 matching lines @@
     if (event->handled())
       return;
   }
 
   if (tooltip_manager_.get())
     tooltip_manager_->UpdateTooltip();
   delegate_->OnMouseEvent(event);
 }
 
 void NativeWidgetAura::OnScrollEvent(ui::ScrollEvent* event) {
-  if (event->type() == ui::ET_SCROLL) {
-    delegate_->OnScrollEvent(event);
-    if (event->handled())
-      return;
-
-    // Convert unprocessed scroll events into wheel events.
-    ui::MouseWheelEvent mwe(*static_cast<ui::ScrollEvent*>(event));
-    delegate_->OnMouseEvent(&mwe);
-    if (mwe.handled())
-      event->SetHandled();
-    return;
-  }
   delegate_->OnScrollEvent(event);
 }
 
 void NativeWidgetAura::OnTouchEvent(ui::TouchEvent* event) {
   DCHECK(window_->IsVisible());
   delegate_->OnTouchEvent(event);
 }
 
 void NativeWidgetAura::OnGestureEvent(ui::GestureEvent* event) {
   DCHECK(window_->IsVisible());
@@ skipping 245 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