ozone: evdev: Remove native size member from TouchEventConverterEvdev

This used to store the original size prior to calibration but that
changed in r304472 ("Keep track of window -> displays mapping"). It no
longer behaves as documented & isn't necessary, so remove it.

TEST=compile
BUG=none

Review URL: https://codereview.chromium.org/1035513002

Cr-Commit-Position: refs/heads/master@{#322046}

ui/events/ozone/evdev/touch_event_converter_evdev.cc

@@ -114,8 +114,6 @@ void TouchEventConverterEvdev::Initialize(const EventDeviceInfo& info) {
                                   cal.bezel_bottom);
   }
 
-  native_size_ = gfx::Size(x_num_tuxels_, y_num_tuxels_);
-
   events_.resize(touch_points_);
   for (size_t i = 0; i < events_.size(); ++i) {
     events_[i].finger_ = info.GetSlotValue(ABS_MT_TRACKING_ID, i);
@@ -143,7 +141,7 @@ bool TouchEventConverterEvdev::HasTouchscreen() const {
 }
 
 gfx::Size TouchEventConverterEvdev::GetTouchscreenSize() const {
-  return native_size_;
+  return gfx::Size(x_num_tuxels_, y_num_tuxels_);
 }
 
 int TouchEventConverterEvdev::GetTouchPoints() const {

ui/events/ozone/evdev/touch_event_converter_evdev.h

@@ -89,9 +89,6 @@ class EVENTS_OZONE_EVDEV_EXPORT TouchEventConverterEvdev
   float y_min_tuxels_;
   float y_num_tuxels_;
 
-  // Size of the touchscreen as reported by the driver.
-  gfx::Size native_size_;
-
   // Number of touch points reported by driver
   int touch_points_;