Fix mouse wheel events processing.

ui/views/widget/widget_unittest.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 <algorithm>
 #include <memory>
 #include <set>
 
 #include "base/bind.h"
 #include "base/macros.h"
@@ skipping 3609 matching lines @@
   EXPECT_FALSE(removals_observer.DidRemoveView(child));
 
   // Moving the child to a different widget should call the removals observer.
   WidgetAutoclosePtr widget2(CreateTopLevelPlatformWidget());
   widget2->client_view()->AddChildView(child);
   EXPECT_TRUE(removals_observer.DidRemoveView(child));
 
   widget->RemoveRemovalsObserver(&removals_observer);
 }
 
+// Test dispatch of ui::ET_MOUSEWHEEL.
+TEST_F(WidgetTest, MouseWheelEvent) {
+  WidgetAutoclosePtr widget(CreateTopLevelPlatformWidget());
+  widget->SetBounds(gfx::Rect(0, 0, 600, 600));
+  EventCountView* event_count_view = new EventCountView();
+  widget->GetContentsView()->AddChildView(event_count_view);
+  event_count_view->SetBounds(0, 0, 600, 600);
+  widget->Show();
+
+  ui::test::EventGenerator event_generator(GetContext(),
+                                           widget->GetNativeWindow());
+
+  event_generator.MoveMouseWheel(1, 1);
+  EXPECT_EQ(1, event_count_view->GetEventCount(ui::ET_MOUSEWHEEL));
+}
+
 #if defined(OS_WIN)
 
 namespace {
 
 // Provides functionality to create a window modal dialog.
 class ModalDialogDelegate : public DialogDelegateView {
 public:
   explicit ModalDialogDelegate(ui::ModalType type) : type_(type) {}
   ~ModalDialogDelegate() override {}
 
@@ skipping 187 matching lines @@
     Transparency_DesktopWidgetTranslucent
 #endif
 TEST_F(CompositingWidgetTest, MAYBE_Transparency_DesktopWidgetTranslucent) {
   CheckAllWidgetsForOpacity(Widget::InitParams::TRANSLUCENT_WINDOW);
 }
 
 #endif  // !defined(OS_CHROMEOS)
 
 }  // namespace test
 }  // namespace views