ozone: evdev: Add a couple more trace events

ui/events/ozone/evdev/touch_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/touch_event_converter_evdev.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/input.h>
 #include <poll.h>
 #include <stdio.h>
 #include <unistd.h>
 
 #include <cmath>
 #include <limits>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/scoped_vector.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
+#include "base/trace_event/trace_event.h"
 #include "ui/events/devices/device_data_manager.h"
 #include "ui/events/devices/device_util_linux.h"
 #include "ui/events/event.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/event_switches.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/ozone/evdev/device_event_dispatcher_evdev.h"
 #include "ui/events/ozone/evdev/touch_evdev_types.h"
 #include "ui/events/ozone/evdev/touch_noise/touch_noise_finder.h"
 
@@ skipping 171 matching lines @@
 
 int TouchEventConverterEvdev::GetTouchPoints() const {
   return touch_points_;
 }
 
 void TouchEventConverterEvdev::OnStopped() {
   ReleaseTouches();
 }
 
 void TouchEventConverterEvdev::OnFileCanReadWithoutBlocking(int fd) {
+  TRACE_EVENT1("evdev",
+               "TouchEventConverterEvdev::OnFileCanReadWithoutBlocking", "fd",
+               fd);
+
   input_event inputs[kNumTouchEvdevSlots * 6 + 1];
   ssize_t read_size = read(fd, inputs, sizeof(inputs));
   if (read_size < 0) {
     if (errno == EINTR || errno == EAGAIN)
       return;
     if (errno != ENODEV)
       PLOG(ERROR) << "error reading device " << path_.value();
     Stop();
     return;
   }
@@ skipping 193 matching lines @@
   if (pressure_max_ - pressure_min_)
     pressure /= pressure_max_ - pressure_min_;
   return pressure;
 }
 
 int TouchEventConverterEvdev::NextTrackingId() {
   return next_tracking_id_++ & kMaxTrackingId;
 }
 
 }  // namespace ui