Experimental app list slide animation is now horizontal, not vertical.

ui/app_list/views/apps_grid_view.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/views/apps_grid_view.h"
 
 #include <algorithm>
 #include <set>
 #include <string>
 
@@ skipping 340 matching lines @@
       drag_pointer_(NONE),
       drop_attempt_(DROP_FOR_NONE),
       drag_and_drop_host_(NULL),
       forward_events_to_drag_and_drop_host_(false),
       page_flip_target_(-1),
       page_flip_delay_in_ms_(kPageFlipDelayInMs),
       bounds_animator_(this),
       activated_folder_item_view_(NULL),
       dragging_for_reparent_item_(false) {
   SetPaintToLayer(true);
+  // Clip any icons that are outside the grid view's bounds. These icons would
+  // otherwise be visible to the user when the grid view is off screen.
+  layer()->SetMasksToBounds(true);
   SetFillsBoundsOpaquely(false);
 
   pagination_model_->AddObserver(this);
   AddChildView(page_switcher_view_);
 }
 
 AppsGridView::~AppsGridView() {
   // Coming here |drag_view_| should already be canceled since otherwise the
   // drag would disappear after the app list got animated away and closed,
   // which would look odd.
@@ skipping 1777 matching lines @@
 void AppsGridView::SetAsFolderDroppingTarget(const Index& target_index,
                                              bool is_target_folder) {
   AppListItemView* target_view =
       static_cast<AppListItemView*>(
           GetViewAtSlotOnCurrentPage(target_index.slot));
   if (target_view)
     target_view->SetAsAttemptedFolderTarget(is_target_folder);
 }
 
 }  // namespace app_list