Move yet more from WmShell to Shell

ash/system/chromeos/power/video_activity_notifier.cc

Index: ash/system/chromeos/power/video_activity_notifier.cc
diff --git a/ash/system/chromeos/power/video_activity_notifier.cc b/ash/system/chromeos/power/video_activity_notifier.cc
index 030e768461d0a5294fc16c728561092fa4c71af5..09360e61a0da4f445f1654cdc3fc7072c597965b 100644
--- a/ash/system/chromeos/power/video_activity_notifier.cc
+++ b/ash/system/chromeos/power/video_activity_notifier.cc
@@ -23,8 +23,7 @@ const int kNotifyIntervalSec = 5;
 VideoActivityNotifier::VideoActivityNotifier(VideoDetector* detector)
     : detector_(detector),
       video_state_(detector->state()),
-      screen_is_locked_(
-          WmShell::Get()->session_controller()->IsScreenLocked()) {
+      screen_is_locked_(Shell::Get()->session_controller()->IsScreenLocked()) {
   detector_->AddObserver(this);
   Shell::GetInstance()->AddShellObserver(this);