cros: Default to natural scrolling if the internal diplay is a touchscreen.

ui/events/event_utils.h

 // 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.
 
 #ifndef UI_EVENTS_EVENT_UTILS_H_
 #define UI_EVENTS_EVENT_UTILS_H_
 
 #include "base/event_types.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/keycodes/keyboard_codes.h"
@@ skipping 106 matching lines @@
 EVENTS_EXPORT bool GetGestureTimes(const base::NativeEvent& native_event,
                                double* start_time,
                                double* end_time);
 
 // Enable/disable natural scrolling for touchpads.
 EVENTS_EXPORT void SetNaturalScroll(bool enabled);
 
 // In natural scrolling enabled for touchpads?
 EVENTS_EXPORT bool IsNaturalScrollEnabled();
 
+// Returns whether natural scrolling should be used for touchpad.
+EVENTS_EXPORT bool ShouldDefaultToNaturalScroll();
+
 // Was this event generated by a touchpad device?
 // The caller is responsible for ensuring that this is a mouse/touchpad event
 // before calling this function.
 EVENTS_EXPORT bool IsTouchpadEvent(const base::NativeEvent& event);
 
 // Returns true if event is noop.
 EVENTS_EXPORT bool IsNoopEvent(const base::NativeEvent& event);
 
 // Creates and returns no-op event.
 EVENTS_EXPORT base::NativeEvent CreateNoopEvent();
@@ skipping 10 matching lines @@
 // Returns true if default post-target handling was canceled for |event| after
 // its dispatch to its target.
 EVENTS_EXPORT bool EventCanceledDefaultHandling(const Event& event);
 
 // Registers a custom event type.
 EVENTS_EXPORT int RegisterCustomEventType();
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_UTILS_H_