ozone: Add some tracing for platform & evdev

ui/events/ozone/evdev/event_factory.cc

 // Copyright 2013 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/event_factory.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/input.h>
 #include <poll.h>
 #include <unistd.h>
 
+#include "base/debug/trace_event.h"
 #include "base/files/file_enumerator.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
 #include "ui/events/ozone/evdev/event_device_info.h"
 #include "ui/events/ozone/evdev/key_event_converter.h"
 #include "ui/events/ozone/evdev/touch_event_converter.h"
 #include "ui/events/ozone/event_factory_ozone.h"
 
 namespace ui {
 
@@ skipping 11 matching lines @@
   return devinfo.HasEventType(EV_ABS) && !IsTouchPad(devinfo);
 }
 
 }  // namespace
 
 EventFactoryEvdev::EventFactoryEvdev() {}
 
 EventFactoryEvdev::~EventFactoryEvdev() {}
 
 void EventFactoryEvdev::AttachInputDevice(const base::FilePath& path) {
+  TRACE_EVENT1("ozone", "AttachInputDevice", "path", path.value());
+
   int fd = open(path.value().c_str(), O_RDONLY | O_NONBLOCK);
   if (fd < 0) {
     PLOG(ERROR) << "Cannot open '" << path.value();
     return;
   }
 
   EventDeviceInfo devinfo;
   if (!devinfo.Initialize(fd)) {
     LOG(ERROR) << "failed to get device information for " << path.value();
     close(fd);
@@ skipping 24 matching lines @@
   base::ThreadRestrictions::AssertIOAllowed();
 
   base::FileEnumerator file_enum(
       base::FilePath("/dev/input"), false, base::FileEnumerator::FILES);
   for (base::FilePath path = file_enum.Next(); !path.empty();
        path = file_enum.Next())
     AttachInputDevice(path);
 }
 
 }  // namespace ui