chromeos: Sync animation.

ash/launcher/launcher_model_observer.h

Index: ash/launcher/launcher_model_observer.h
diff --git a/ash/launcher/launcher_model_observer.h b/ash/launcher/launcher_model_observer.h
index 5d73d1c786b635ab63348b8e7ae13b9f0d5c9328..4f7f5d5bfdab0e17091ee0853d4be6c2e61ef06e 100644
--- a/ash/launcher/launcher_model_observer.h
+++ b/ash/launcher/launcher_model_observer.h
@@ -25,10 +25,13 @@ class ASH_EXPORT LauncherModelObserver {
   // of the arguments.
   virtual void LauncherItemMoved(int start_index, int target_index) = 0;
 
-  // Invoked when the the state of an item changes. |old_item| is the item
+  // Invoked when the state of an item changes. |old_item| is the item
   // before the change.
   virtual void LauncherItemChanged(int index, const LauncherItem& old_item) = 0;
 
+  // Invoked when the UI state of the model changes.
+  virtual void LauncherUIStateChanged() = 0;
+
  protected:
   virtual ~LauncherModelObserver() {}
 };