Allows observers to be notified when layer animations complete.

ui/aura/desktop.cc

Index: ui/aura/desktop.cc
diff --git a/ui/aura/desktop.cc b/ui/aura/desktop.cc
index 2c747d28beb72b28eb1182e205bcfd9f37ff51e2..507e7c8575dac081ca3a88fe8eaaf6b2123fb568 100644
--- a/ui/aura/desktop.cc
+++ b/ui/aura/desktop.cc
@@ -305,8 +305,10 @@ bool Desktop::DispatchKeyEvent(KeyEvent* event) {
       if (degrees != 0) {
         layer()->GetAnimator()->set_preemption_strategy(
             ui::LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
-        layer()->GetAnimator()->ScheduleAnimationElement(
-            new ScreenRotation(degrees));
+        scoped_ptr<ui::LayerAnimationSequence> screen_rotation(
+            new ui::LayerAnimationSequence(new ScreenRotation(degrees)));
+        screen_rotation->AddObserver(this);
+        layer()->GetAnimator()->ScheduleAnimation(screen_rotation.release());
         return true;
       }
     }