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

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

Index: ui/ozone/platform/drm/gpu/drm_device.cc
diff --git a/ui/ozone/platform/drm/gpu/drm_device.cc b/ui/ozone/platform/drm/gpu/drm_device.cc
index fb5bbc8d4d080a2fcd397d1b3dc54801c853d3be..4d2bcbfe9894496e5c73d91c8282691f8d15d898 100644
--- a/ui/ozone/platform/drm/gpu/drm_device.cc
+++ b/ui/ozone/platform/drm/gpu/drm_device.cc
@@ -232,6 +232,8 @@ bool DrmDevice::Initialize() {
         << "': " << 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