chromeos: Sync animation.

ash/launcher/launcher_model.h

Index: ash/launcher/launcher_model.h
diff --git a/ash/launcher/launcher_model.h b/ash/launcher/launcher_model.h
index d4cd05eb367b522fb15c1bca1c0a95e3b2a65f36..374566e1eaaea0fffb45492036e3fd119b7249d0 100644
--- a/ash/launcher/launcher_model.h
+++ b/ash/launcher/launcher_model.h
@@ -22,6 +22,12 @@ class LauncherModelObserver;
 // Model used by LauncherView.
 class ASH_EXPORT LauncherModel {
  public:
+  enum UIState {
+    NORMAL,
+    // In this state, Launcher shows a loading animation.
+    LOADING,
+  };
+
   LauncherModel();
   ~LauncherModel();
 
@@ -59,16 +65,26 @@ class ASH_EXPORT LauncherModel {
   void AddObserver(LauncherModelObserver* observer);
   void RemoveObserver(LauncherModelObserver* observer);
 
+  void SetUIState(UIState ui_state);
+  UIState ui_state() const { return ui_state_; }
+
  private:
   // Makes sure |index| is in line with the type-based order of items. If that
   // is not the case, adjusts index by shifting it to the valid range and
   // returns the new value.
   int ValidateInsertionIndex(LauncherItemType type, int index) const;
 
+  // Gets desired number of loading placeholders.
+  int GetDesiredNumOfPlaceholders();
+
+  // Ensures the model has exactly |n| loading placeholders.
+  void UpdatePlaceholders(int n);
+
   // ID assigned to the next item.
   LauncherID next_id_;
   LauncherItems items_;
   ObserverList<LauncherModelObserver> observers_;
+  UIState ui_state_;
 
   DISALLOW_COPY_AND_ASSIGN(LauncherModel);
 };