Use the location where FileDescriptorWatcher is created to track the libevent handlers

ui/events/ozone/evdev/tablet_event_converter_evdev.cc

 // Copyright 2014 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 "ui/events/ozone/evdev/tablet_event_converter_evdev.h"
 
 #include <errno.h>
 #include <linux/input.h>
 #include <stddef.h>
 
@@ skipping 27 matching lines @@
     const EventDeviceInfo& info,
     DeviceEventDispatcherEvdev* dispatcher)
     : EventConverterEvdev(fd.get(),
                           path,
                           id,
                           info.device_type(),
                           info.name(),
                           info.vendor_id(),
                           info.product_id()),
       input_device_fd_(std::move(fd)),
+      controller_(FROM_HERE),
       cursor_(cursor),
       dispatcher_(dispatcher) {
   x_abs_min_ = info.GetAbsMinimum(ABS_X);
   x_abs_range_ = info.GetAbsMaximum(ABS_X) - x_abs_min_ + 1;
   y_abs_min_ = info.GetAbsMinimum(ABS_Y);
   y_abs_range_ = info.GetAbsMaximum(ABS_Y) - y_abs_min_ + 1;
   tilt_x_min_ = info.GetAbsMinimum(ABS_TILT_X);
   tilt_y_min_ = info.GetAbsMinimum(ABS_TILT_Y);
   tilt_x_range_ = info.GetAbsMaximum(ABS_TILT_X) - tilt_x_min_ + 1;
   tilt_y_range_ = info.GetAbsMaximum(ABS_TILT_Y) - tilt_y_min_ + 1;
@@ skipping 154 matching lines @@
       input_device_.id, EF_NONE, cursor_->GetLocation(),
       PointerDetails(GetToolType(stylus_),
                      /* radius_x */ 0.0f, /* radius_y */ 0.0f, pressure_,
                      tilt_x_, tilt_y_),
       TimeTicksFromInputEvent(input)));
 
   abs_value_dirty_ = false;
 }
 
 }  // namespace ui