app_list: Make over scroll animation faster.

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 41 matching lines @@
 
   void SetTotalPages(int total_pages);
 
   // Selects a page. |animate| is true if the transition should be animated.
   void SelectPage(int page, bool animate);
 
   // Selects a page by relative |delta|.
   void SelectPageRelative(int delta, bool animate);
 
   void SetTransition(const Transition& transition);
-  void SetTransitionDuration(int duration_ms);
+  void SetTransitionDurations(int duration_ms, int overscroll_duration_ms);
 
   // Starts a scroll transition. If there is a running transition animation,
   // cancels it but keeps the transition info.
   void StartScroll();
 
   // 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);
 
@@ skipping 28 matching lines @@
   }
 
   // Calculates a target page number by combining current page and |delta|.
   // When there is no transition, current page is the currently selected page.
   // If there is a transition, current page is the transition target page or the
   // pending transition target page. When current page + |delta| goes beyond
   // valid range and |selected_page_| is at the range ends, invalid page number
   // -1 or |total_pages_| is returned to indicate the situation.
   int CalculateTargetPage(int delta) const;
 
-  void StartTranstionAnimation(int target_page);
-  void CreateTransitionAnimation();
+  void StartTransitionAnimation(const Transition& transition);
   void ResetTransitionAnimation();
 
   // 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_;
 
   // 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.
+  int overscroll_transition_duration_ms_;
 
   ObserverList<PaginationModelObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(PaginationModel);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_PAGINATION_MODEL_H_