ozone: evdev: Add a couple more trace events

ui/events/ozone/evdev/libgestures_glue/event_reader_libevdev_cros.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/libgestures_glue/event_reader_libevdev_cros.h"
 
 #include <errno.h>
 #include <libevdev/libevdev.h>
 #include <linux/input.h>
 
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
+#include "base/trace_event/trace_event.h"
 
 namespace ui {
 
 namespace {
 
 std::string FormatLog(const char* fmt, va_list args) {
   std::string msg = base::StringPrintV(fmt, args);
   if (!msg.empty() && msg[msg.size() - 1] == '\n')
     msg.erase(msg.end() - 1, msg.end());
   return msg;
@@ skipping 39 matching lines @@
 }
 
 EventReaderLibevdevCros::~EventReaderLibevdevCros() {
   Stop();
   EvdevClose(&evdev_);
 }
 
 EventReaderLibevdevCros::Delegate::~Delegate() {}
 
 void EventReaderLibevdevCros::OnFileCanReadWithoutBlocking(int fd) {
+  TRACE_EVENT1("evdev", "EventReaderLibevdevCros::OnFileCanReadWithoutBlocking",
+               "fd", fd);
+
   if (EvdevRead(&evdev_)) {
     if (errno == EINTR || errno == EAGAIN)
       return;
     if (errno != ENODEV)
       PLOG(ERROR) << "error reading device " << path_.value();
     Stop();
     return;
   }
 }
 
@@ skipping 38 matching lines @@
   if (level >= LOGLEVEL_ERROR)
     LOG(ERROR) << "libevdev: " << FormatLog(fmt, args);
   else if (level >= LOGLEVEL_WARNING)
     LOG(WARNING) << "libevdev: " << FormatLog(fmt, args);
   else
     VLOG(3) << "libevdev: " << FormatLog(fmt, args);
   va_end(args);
 }
 
 }  // namespace ui