Create MouseWheelEvent directly instead of through MouseEvent.

ash/sticky_keys/sticky_keys_unittest.cc

 // Copyright 2013 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 "ash/sticky_keys/sticky_keys_controller.h"
 
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 143 matching lines @@
 
   // Creates a synthesized KeyEvent that is not backed by a native event.
   ui::KeyEvent* GenerateSynthesizedKeyEvent(ui::EventType type,
                                             ui::KeyboardCode code) {
     return new ui::KeyEvent(type, code, ui::EF_NONE);
   }
 
   // Creates a synthesized MouseEvent that is not backed by a native event.
   ui::MouseEvent* GenerateSynthesizedMouseEventAt(ui::EventType event_type,
                                                   const gfx::Point& location) {
-    ui::MouseEvent* event = new ui::MouseEvent(
-        event_type, location, location, ui::EventTimeForNow(),
-        ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON);
+    ui::MouseEvent* event;
+    if (event_type == ui::ET_MOUSEWHEEL) {
+      event = new ui::MouseWheelEvent(
+          gfx::Vector2d(), location, location, ui::EventTimeForNow(),
+          ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON);
+    } else {
+      event = new ui::MouseEvent(
+          event_type, location, location, ui::EventTimeForNow(),
+          ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON);
+    }
     ui::Event::DispatcherApi dispatcher(event);
     dispatcher.set_target(target_);
     return event;
   }
 
   // Creates a synthesized mouse press or release event.
   ui::MouseEvent* GenerateSynthesizedMouseClickEvent(
       ui::EventType type,
       const gfx::Point& location) {
     return GenerateSynthesizedMouseEventAt(type, location);
@@ skipping 558 matching lines @@
                                                gfx::Point(0, 0)));
   released = false;
   mod_down_flags = 0;
   sticky_key.HandleMouseEvent(*mev.get(), &mod_down_flags, &released);
   EXPECT_TRUE(mod_down_flags & ui::EF_CONTROL_DOWN);
   EXPECT_TRUE(released);
   EXPECT_EQ(STICKY_KEY_STATE_DISABLED, sticky_key.current_state());
 }
 
 }  // namespace ash