[Ozone-Drm] Revert of holding on to the DRM FDs in the browser process

ui/ozone/platform/drm/host/drm_device_handle.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/host/drm_device_handle.h"
 
 #include <fcntl.h>
 #include <xf86drm.h>
 #include <xf86drmMode.h>
 
@@ skipping 12 matching lines @@
   // authentication logic to figure out if the device has enough permissions.
   return !drmGetMagic(fd, &magic) && !drmAuthMagic(fd, magic);
 }
 
 }  // namespace
 
 DrmDeviceHandle::DrmDeviceHandle() {
 }
 
 DrmDeviceHandle::~DrmDeviceHandle() {
-  base::ThreadRestrictions::AssertIOAllowed();
+  if (file_.is_valid())
+    base::ThreadRestrictions::AssertIOAllowed();
 }
 
 bool DrmDeviceHandle::Initialize(const base::FilePath& path) {
   CHECK(path.DirName() == base::FilePath("/dev/dri"));
   base::ThreadRestrictions::AssertIOAllowed();
   bool print_warning = true;
   while (true) {
     file_.reset();
     int fd = HANDLE_EINTR(open(path.value().c_str(), O_RDWR | O_CLOEXEC));
     if (fd < 0) {
@@ skipping 12 matching lines @@
   }
 
   VLOG(1) << "Succeeded authenticating " << path.value();
   return true;
 }
 
 bool DrmDeviceHandle::IsValid() const {
   return file_.is_valid();
 }
 
-base::ScopedFD DrmDeviceHandle::Duplicate() {
-  DCHECK(file_.is_valid());
-  int fd = dup(file_.get());
-  if (fd < 0) {
-    PLOG(ERROR) << "Failed to dup";
-    return base::ScopedFD();
-  }
-
-  return base::ScopedFD(fd);
+base::ScopedFD DrmDeviceHandle::PassFD() {
+  return file_.Pass();
 }
 
 }  // namespace ui