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

ui/events/gesture_detection/motion_event_generic.h

Index: ui/events/gesture_detection/motion_event_generic.h
diff --git a/ui/events/gesture_detection/motion_event_generic.h b/ui/events/gesture_detection/motion_event_generic.h
index 9d7733fafd1a0d5d57aa42a6d7af14bc276ddd57..a0d9619e5d58b1271db35e6b170fcb8cf89b5588 100644
--- a/ui/events/gesture_detection/motion_event_generic.h
+++ b/ui/events/gesture_detection/motion_event_generic.h
@@ -28,6 +28,8 @@ struct GESTURE_DETECTION_EXPORT PointerProperties {
   float touch_major;
   float touch_minor;
   float orientation;
+  float tilt;
+  float tiltDirection;
   // source_device_id is only used on Aura.
   int source_device_id;
 };
@@ -55,6 +57,8 @@ class GESTURE_DETECTION_EXPORT MotionEventGeneric : public MotionEvent {
   float GetTouchMajor(size_t pointer_index) const override;
   float GetTouchMinor(size_t pointer_index) const override;
   float GetOrientation(size_t pointer_index) const override;
+  float GetTilt(size_t pointer_index) const override;
+  float GetTiltDirection(size_t pointer_index) const override;
   float GetPressure(size_t pointer_index) const override;
   ToolType GetToolType(size_t pointer_index) const override;
   int GetButtonState() const override;