[Ozone-Drm] Add log message when the DRM device is authenticated

ui/ozone/platform/drm/gpu/drm_device.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/ozone/platform/drm/gpu/drm_device.h"
 
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <unistd.h>
 #include <xf86drm.h>
@@ skipping 214 matching lines @@
 
     usleep(100000);
     file_ =
         base::File(device_path_, base::File::FLAG_OPEN | base::File::FLAG_READ |
                                      base::File::FLAG_WRITE);
     LOG_IF(FATAL, !file_.IsValid())
         << "Failed to open '" << device_path_.value()
         << "': " << base::File::ErrorToString(file_.error_details());
   }
 
+  VLOG(1) << "Succeeded in taking master on " << device_path_.value();
+
 #if defined(USE_DRM_ATOMIC)
   plane_manager_.reset(new HardwareDisplayPlaneManagerAtomic());
 #else
   plane_manager_.reset(new HardwareDisplayPlaneManagerLegacy());
 #endif  // defined(USE_DRM_ATOMIC)
   if (!plane_manager_->Initialize(this)) {
     LOG(ERROR) << "Failed to initialize the plane manager for "
                << device_path_.value();
     plane_manager_.reset();
     return false;
@@ skipping 253 matching lines @@
   DCHECK(file_.IsValid());
   return (drmSetMaster(file_.GetPlatformFile()) == 0);
 }
 
 bool DrmDevice::DropMaster() {
   DCHECK(file_.IsValid());
   return (drmDropMaster(file_.GetPlatformFile()) == 0);
 }
 
 }  // namespace ui