[Ozone-Drm] Change file locking from Posix to BSD style

ui/ozone/platform/drm/gpu/gpu_lock.cc

 // Copyright 2015 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/ozone/platform/drm/gpu/gpu_lock.h"
 
-#include <fcntl.h>
+#include <sys/file.h>
 #include <unistd.h>
 
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 
 namespace ui {
 
 namespace {
 const char kGpuLockFile[] = "/run/frecon";
 }
 
 GpuLock::GpuLock() {
   fd_ = open(kGpuLockFile, O_RDWR);
   if (fd_ < 0) {
     PLOG(ERROR) << "Failed to open lock file '" << kGpuLockFile << "'";
     return;
   }
 
-  struct flock data;
-  memset(&data, 0, sizeof(data));
-  data.l_type = F_WRLCK;
-  data.l_whence = SEEK_SET;
-
   VLOG(1) << "Taking write lock on '" << kGpuLockFile << "'";
-  if (HANDLE_EINTR(fcntl(fd_, F_SETLKW, &data)))
+  if (HANDLE_EINTR(flock(fd_, LOCK_EX)))
     PLOG(ERROR) << "Error while trying to get lock on '" << kGpuLockFile << "'";
 
   VLOG(1) << "Done trying to take write lock on '" << kGpuLockFile << "'";
 }
 
 GpuLock::~GpuLock() {
   // Failed to open the lock file, so nothing to do here.
   if (fd_ < 0)
     return;
 
   VLOG(1) << "Releasing write lock on '" << kGpuLockFile << "'";
   close(fd_);
 }
 
 }  // namespace ui