cros: Use SessionController for lock starting code

chrome/browser/ui/ash/session_controller_client.h

Index: chrome/browser/ui/ash/session_controller_client.h
diff --git a/chrome/browser/ui/ash/session_controller_client.h b/chrome/browser/ui/ash/session_controller_client.h
index ab9ba3f9c855aefe834891e15d4effed9a38af47..c2fcd9a9dd7c5f56d0acd11fb4422107f196631e 100644
--- a/chrome/browser/ui/ash/session_controller_client.h
+++ b/chrome/browser/ui/ash/session_controller_client.h
@@ -37,6 +37,11 @@ class SessionControllerClient
 
   static SessionControllerClient* Get();
 
+  // Calls ash SessionController to run lock animation to start lock.
+  // |animation_finished_callback| will be invoked when the post lock animation
+  // finishes and the system is fully locked.
+  void RunLockAnimation(base::Closure animation_finished_callback);
+
   // Calls ash SessionController to run unlock animation.
   // |animation_finished_callback| will be invoked when the animation finishes.
   void RunUnlockAnimation(base::Closure animation_finished_callback);