cros: Fix mouse over-scroll animation not happening.

ui/app_list/pagination_model.cc

 // 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.
 
 #include "ui/app_list/pagination_model.h"
 
 #include <algorithm>
 
 #include "ui/app_list/pagination_model_observer.h"
 #include "ui/base/animation/slide_animation.h"
 
 namespace app_list {
 
 PaginationModel::PaginationModel()
     : total_pages_(-1),
       selected_page_(-1),
       transition_(-1, 0),
-      scrolling_(false),
       pending_selected_page_(-1),
       transition_duration_ms_(0) {
 }
 
 PaginationModel::~PaginationModel() {
 }
 
 void PaginationModel::SetTotalPages(int total_pages) {
   if (total_pages == total_pages_)
     return;
@@ skipping 65 matching lines @@
 
   transition_ = transition;
   NotifyTransitionChanged();
 }
 
 void PaginationModel::SetTransitionDuration(int duration_ms) {
   transition_duration_ms_ = duration_ms;
 }
 
 void PaginationModel::StartScroll() {
-  scrolling_ = true;
   // Cancels current transition animation (if any).
   transition_animation_.reset();
 }
 
 void PaginationModel::UpdateScroll(double delta) {
   // Translates scroll delta to desired page change direction.
   int page_change_dir = delta > 0 ? -1 : 1;
 
   // Initializes a transition if there is none.
   if (!has_transition())
@@ skipping 11 matching lines @@
       SelectPage(transition_.target_page, false);
       clear_transition();
     }
   } else {
     transition_.progress = progress;
     NotifyTransitionChanged();
   }
 }
 
 void PaginationModel::EndScroll(bool cancel) {
-  scrolling_ = false;
-
   if (!has_transition())
     return;
 
   CreateTransitionAnimation();
   transition_animation_->Reset(transition_.progress);
 
   // Always call Show to ensure animation will run.
   transition_animation_->Show();
   if (cancel)
     transition_animation_->Hide();
 }
 
+bool PaginationModel::IsRevertingCurrentTransition() const {
+  return transition_animation_.get() && transition_animation_->IsClosing();
+}
+
 void PaginationModel::AddObserver(PaginationModelObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void PaginationModel::RemoveObserver(PaginationModelObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 void PaginationModel::NotifySelectedPageChanged(int old_selected,
                                                 int new_selected) {
@@ skipping 76 matching lines @@
   } else if (transition_animation_->GetCurrentValue() == 0) {
     // Hiding animation ends. No page change should happen.
     ResetTransitionAnimation();
   }
 
   if (next_target >= 0)
     SelectPage(next_target, true);
 }
 
 }  // namespace app_list