Added experimental Touch.tilt, Touch.tiltDirection support for Android

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/basictypes.h"
 #include "base/event_types.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 109 matching lines @@
 EVENTS_EXPORT void ClearTouchIdIfReleased(
     const base::NativeEvent& native_event);
 
 // Gets the radius along the X/Y axis from a native event. Default is 1.0.
 EVENTS_EXPORT float GetTouchRadiusX(const base::NativeEvent& native_event);
 EVENTS_EXPORT float GetTouchRadiusY(const base::NativeEvent& native_event);
 
 // Gets the angle of the major axis away from the X axis. Default is 0.0.
 EVENTS_EXPORT float GetTouchAngle(const base::NativeEvent& native_event);
 
+// Gets the tilt angle of the stylus away from the perpendicular to the screen
+// Default is NaN.
+EVENTS_EXPORT float GetTouchTilt(const base::NativeEvent& native_event);
+
+// Gets the clockwise angle from the X axis to the XY-projection of the stylus.
+// Range is [-180, 180), default is NaN.
+EVENTS_EXPORT float GetTouchTiltDirection(
+    const base::NativeEvent& native_event);
+
 // Gets the force from a native_event. Normalized to be [0, 1]. Default is 0.0.
 EVENTS_EXPORT float GetTouchForce(const base::NativeEvent& native_event);
 
 // Gets the fling velocity from a native event. is_cancel is set to true if
 // this was a tap down, intended to stop an ongoing fling.
 EVENTS_EXPORT bool GetFlingData(const base::NativeEvent& native_event,
                                 float* vx,
                                 float* vy,
                                 float* vx_ordinal,
                                 float* vy_ordinal,
@@ skipping 35 matching lines @@
 // Update the native X11 event to correspond to the new button flags.
 EVENTS_EXPORT void UpdateX11EventForChangedButtonFlags(MouseEvent* event);
 #endif
 
 // Registers a custom event type.
 EVENTS_EXPORT int RegisterCustomEventType();
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_UTILS_H_