cros: Fix mouse over-scroll animation not happening.

ui/app_list/pagination_model.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_APP_LIST_PAGINATION_MODEL_H_
 #define UI_APP_LIST_PAGINATION_MODEL_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 56 matching lines @@
 
   // Updates transition progress from |delta|. |delta| > 0 means transit to
   // previous page (moving pages to the right). |delta| < 0 means transit
   // to next page (moving pages to the left).
   void UpdateScroll(double delta);
 
   // Finishes the current scroll transition if |cancel| is false. Otherwise,
   // reverses it.
   void EndScroll(bool cancel);
 
+  // Returns true if current transition is being reverted.
+  bool IsRevertingCurrentTransition() const;
+
   void AddObserver(PaginationModelObserver* observer);
   void RemoveObserver(PaginationModelObserver* observer);
 
   int total_pages() const { return total_pages_; }
   int selected_page() const { return selected_page_; }
   const Transition& transition() const { return transition_; }
-  bool scrolling() const { return scrolling_; }
 
   bool is_valid_page(int page) const {
     return page >= 0 && page < total_pages_;
   }
 
   bool has_transition() const {
     return transition_.target_page != -1 || transition_.progress != 0;
   }
 
  private:
@@ skipping 18 matching lines @@
 
   // ui::AnimationDelegate overrides:
   virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
   virtual void AnimationEnded(const ui::Animation* animation) OVERRIDE;
 
   int total_pages_;
   int selected_page_;
 
   Transition transition_;
 
-  bool scrolling_;  // Whether a scroll is in progress.
-
   // Pending selected page when SelectedPage is called during a transition. If
   // multiple SelectPage is called while a transition is in progress, only the
   // last target page is remembered here.
   int pending_selected_page_;
 
   scoped_ptr<ui::SlideAnimation> transition_animation_;
   int transition_duration_ms_;  // Transition duration in millisecond.
 
   ObserverList<PaginationModelObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(PaginationModel);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_PAGINATION_MODEL_H_