[cros] Fix udevadm command line for camera presence detection.

chrome/browser/chromeos/login/camera_detector.cc

Index: chrome/browser/chromeos/login/camera_detector.cc
diff --git a/chrome/browser/chromeos/login/camera_detector.cc b/chrome/browser/chromeos/login/camera_detector.cc
index 1ca43ed657452892d6f37b2cb85b22382506e227..06e882b4d50c1ea9cfdfbb69fa0d54b80153a021 100644
--- a/chrome/browser/chromeos/login/camera_detector.cc
+++ b/chrome/browser/chromeos/login/camera_detector.cc
@@ -36,6 +36,8 @@ bool CameraDetector::presence_check_in_progress_ = false;
 void CameraDetector::StartPresenceCheck(const base::Closure& check_done) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
+  DVLOG(1) << "Starting camera presence check";
+
   if (!presence_check_in_progress_) {
     presence_check_in_progress_ = true;
     BrowserThread::PostTaskAndReply(
@@ -75,6 +77,8 @@ void CameraDetector::CheckPresence() {
 
   camera_presence_ = present ? kCameraPresent : kCameraAbsent;
   presence_check_in_progress_ = false;
+
+  DVLOG(1) << "Camera presence state: " << camera_presence_;
 }
 
 }  // namespace chromeos