wip: Refactoring Ash's AppListController, moving the bulk of the logic to chrome/browser/ui/ash/app…

chrome/browser/ui/ash/app_list/app_list_shower_ash.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 "ash/wm/app_list_controller.h"
+#include "chrome/browser/ui/ash/app_list/app_list_shower_ash.h"
 
-#include "ash/ash_switches.h"
-#include "ash/root_window_controller.h"
-#include "ash/screen_util.h"
-#include "ash/shelf/shelf.h"
-#include "ash/shelf/shelf_layout_manager.h"
+#include "ash/metrics/task_switch_metrics_recorder.h"
 #include "ash/shell.h"
-#include "ash/shell_delegate.h"
-#include "ash/shell_window_ids.h"
-#include "ash/wm/maximize_mode/maximize_mode_controller.h"
-#include "base/command_line.h"
+#include "ash/wm/app_list_layout_delegate.h"
+#include "base/memory/singleton.h"
+#include "chrome/browser/ui/app_list/app_list_view_delegate.h"
+#include "chrome/browser/ui/ash/launcher/chrome_launcher_controller.h"
+#include "chrome/browser/ui/browser_navigator.h"
+#include "chrome/browser/ui/browser_navigator_params.h"
+#include "extensions/common/extension.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/app_list/views/app_list_view.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
-#include "ui/aura/window_event_dispatcher.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
-#include "ui/events/event.h"
-#include "ui/gfx/transform_util.h"
 #include "ui/keyboard/keyboard_controller.h"
 #include "ui/views/widget/widget.h"
 
-namespace ash {
 namespace {
 
 // Duration for show/hide animation in milliseconds.
 const int kAnimationDurationMs = 200;
 
-// Offset in pixels to animation away/towards the shelf.
-const int kAnimationOffset = 8;
-
 // The maximum shift in pixels when over-scroll happens.
 const int kMaxOverScrollShift = 48;
 
-// The minimal anchor position offset to make sure that the bubble is still on
-// the screen with 8 pixels spacing on the left / right. This constant is a
-// result of minimal bubble arrow sizes and offsets.
-const int kMinimalAnchorPositionOffset = 57;
-
-// The minimal margin (in pixels) around the app list when in centered mode.
-const int kMinimalCenteredAppListMargin = 10;
-
 ui::Layer* GetLayer(views::Widget* widget) {
   return widget->GetNativeView()->layer();
 }
 
-// Gets arrow location based on shelf alignment.
-views::BubbleBorder::Arrow GetBubbleArrow(aura::Window* window) {
-  DCHECK(Shell::HasInstance());
-  return ShelfLayoutManager::ForShelf(window)->
-      SelectValueForShelfAlignment(
-          views::BubbleBorder::BOTTOM_CENTER,
-          views::BubbleBorder::LEFT_CENTER,
-          views::BubbleBorder::RIGHT_CENTER,
-          views::BubbleBorder::TOP_CENTER);
-}
-
-// Offset given |rect| towards shelf.
-gfx::Rect OffsetTowardsShelf(const gfx::Rect& rect, views::Widget* widget) {
-  DCHECK(Shell::HasInstance());
-  ShelfAlignment shelf_alignment = Shell::GetInstance()->GetShelfAlignment(
-      widget->GetNativeView()->GetRootWindow());
-  gfx::Rect offseted(rect);
-  switch (shelf_alignment) {
-    case SHELF_ALIGNMENT_BOTTOM:
-      offseted.Offset(0, kAnimationOffset);
-      break;
-    case SHELF_ALIGNMENT_LEFT:
-      offseted.Offset(-kAnimationOffset, 0);
-      break;
-    case SHELF_ALIGNMENT_RIGHT:
-      offseted.Offset(kAnimationOffset, 0);
-      break;
-    case SHELF_ALIGNMENT_TOP:
-      offseted.Offset(0, -kAnimationOffset);
-      break;
-  }
-
-  return offseted;
-}
-
-// Using |button_bounds|, determine the anchor offset so that the bubble gets
-// shown above the shelf (used for the alternate shelf theme).
-gfx::Vector2d GetAnchorPositionOffsetToShelf(
-    const gfx::Rect& button_bounds, views::Widget* widget) {
-  DCHECK(Shell::HasInstance());
-  ShelfAlignment shelf_alignment = Shell::GetInstance()->GetShelfAlignment(
-      widget->GetNativeView()->GetRootWindow());
-  gfx::Point anchor(button_bounds.CenterPoint());
-  switch (shelf_alignment) {
-    case SHELF_ALIGNMENT_TOP:
-    case SHELF_ALIGNMENT_BOTTOM:
-      if (base::i18n::IsRTL()) {
-        int screen_width = widget->GetWorkAreaBoundsInScreen().width();
-        return gfx::Vector2d(
-            std::min(screen_width - kMinimalAnchorPositionOffset - anchor.x(),
-                     0), 0);
-      }
-      return gfx::Vector2d(
-          std::max(kMinimalAnchorPositionOffset - anchor.x(), 0), 0);
-    case SHELF_ALIGNMENT_LEFT:
-      return gfx::Vector2d(
-          0, std::max(kMinimalAnchorPositionOffset - anchor.y(), 0));
-    case SHELF_ALIGNMENT_RIGHT:
-      return gfx::Vector2d(
-          0, std::max(kMinimalAnchorPositionOffset - anchor.y(), 0));
-    default:
-      NOTREACHED();
-      return gfx::Vector2d();
-  }
-}
-
-// Gets the point at the center of the display that a particular view is on.
-// This calculation excludes the virtual keyboard area. If the height of the
-// display area is less than |minimum_height|, its bottom will be extended to
-// that height (so that the app list never starts above the top of the screen).
-gfx::Point GetCenterOfDisplayForView(const views::View* view,
-                                     int minimum_height) {
-  aura::Window* window = view->GetWidget()->GetNativeView();
-  gfx::Rect bounds = ScreenUtil::GetShelfDisplayBoundsInRoot(window);
-  bounds = ScreenUtil::ConvertRectToScreen(window->GetRootWindow(), bounds);
-
-  // If the virtual keyboard is active, subtract it from the display bounds, so
-  // that the app list is centered in the non-keyboard area of the display.
-  // (Note that work_area excludes the keyboard, but it doesn't get updated
-  // until after this function is called.)
-  keyboard::KeyboardController* keyboard_controller =
-      keyboard::KeyboardController::GetInstance();
-  if (keyboard_controller && keyboard_controller->keyboard_visible())
-    bounds.Subtract(keyboard_controller->current_keyboard_bounds());
-
-  // Apply the |minimum_height|.
-  if (bounds.height() < minimum_height)
-    bounds.set_height(minimum_height);
-
-  return bounds.CenterPoint();
-}
-
-// Gets the minimum height of the rectangle to center the app list in.
-int GetMinimumBoundsHeightForAppList(const app_list::AppListView* app_list) {
-  return app_list->bounds().height() + 2 * kMinimalCenteredAppListMargin;
-}
-
-bool IsFullscreenAppListEnabled() {
-#if defined(OS_CHROMEOS)
-  return base::CommandLine::ForCurrentProcess()->HasSwitch(
-             switches::kAshEnableFullscreenAppList) &&
-         app_list::switches::IsExperimentalAppListEnabled();
-#else
-  return false;
-#endif
-}
-
 }  // namespace
 
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, public:
+AppListShowerAsh::AppListShowerAsh()
+    : view_delegate_(nullptr),
+      is_visible_(false),
+      view_(nullptr),
+      current_apps_page_(-1),
+      should_snap_back_(false) {}
 
-AppListController::AppListController()
-    : is_visible_(false),
-      is_centered_(false),
-      view_(NULL),
-      current_apps_page_(-1),
-      should_snap_back_(false) {
-  Shell::GetInstance()->AddShellObserver(this);
-}
-
-AppListController::~AppListController() {
+AppListShowerAsh::~AppListShowerAsh() {
+  layout_delegate_.reset();
   // Ensures app list view goes before the controller since pagination model
   // lives in the controller and app list view would access it on destruction.
   if (view_) {
     view_->GetAppsPaginationModel()->RemoveObserver(this);
     if (view_->GetWidget())
       view_->GetWidget()->CloseNow();
   }
-
-  Shell::GetInstance()->RemoveShellObserver(this);
 }
 
-void AppListController::Show(aura::Window* window) {
+aura::Window* AppListShowerAsh::GetWindow() {
+  return is_visible_ && view_ ? view_->GetWidget()->GetNativeWindow() : nullptr;
+}
+
+void AppListShowerAsh::Show(aura::Window* window) {
   if (is_visible_)
     return;
 
+  DCHECK(view_delegate_);
   is_visible_ = true;
 
-  // App list needs to know the new shelf layout in order to calculate its
-  // UI layout when AppListView visibility changes.
-  Shell::GetPrimaryRootWindowController()->GetShelfLayoutManager()->
-      UpdateAutoHideState();
-
+  aura::Window* root_window = window->GetRootWindow();
   if (view_) {
     ScheduleAnimation();
   } else {
     // Note the AppListViewDelegate outlives the AppListView. For Ash, the view
     // is destroyed when dismissed.
-    app_list::AppListView* view = new app_list::AppListView(
-        Shell::GetInstance()->delegate()->GetAppListViewDelegate());
-    aura::Window* root_window = window->GetRootWindow();
-    aura::Window* container = GetRootWindowController(root_window)->
-        GetContainer(kShellWindowId_AppListContainer);
-    views::View* applist_button =
-        Shelf::ForWindow(container)->GetAppListButtonView();
-    is_centered_ = view->ShouldCenterWindow();
-    bool is_fullscreen = IsFullscreenAppListEnabled() &&
-                         Shell::GetInstance()
-                             ->maximize_mode_controller()
-                             ->IsMaximizeModeWindowManagerEnabled();
-    if (is_fullscreen) {
-      view->InitAsFramelessWindow(
-          container, current_apps_page_,
-          ScreenUtil::GetDisplayWorkAreaBoundsInParent(container));
-    } else if (is_centered_) {
-      // Note: We can't center the app list until we have its dimensions, so we
-      // init at (0, 0) and then reset its anchor point.
-      view->InitAsBubbleAtFixedLocation(container,
-                                        current_apps_page_,
-                                        gfx::Point(),
-                                        views::BubbleBorder::FLOAT,
-                                        true /* border_accepts_events */);
-      // The experimental app list is centered over the display of the app list
-      // button that was pressed (if triggered via keyboard, this is the display
-      // with the currently focused window).
-      view->SetAnchorPoint(GetCenterOfDisplayForView(
-          applist_button, GetMinimumBoundsHeightForAppList(view)));
-    } else {
-      gfx::Rect applist_button_bounds = applist_button->GetBoundsInScreen();
-      // We need the location of the button within the local screen.
-      applist_button_bounds = ScreenUtil::ConvertRectFromScreen(
-          root_window,
-          applist_button_bounds);
-      view->InitAsBubbleAttachedToAnchor(
-          container,
-          current_apps_page_,
-          Shelf::ForWindow(container)->GetAppListButtonView(),
-          GetAnchorPositionOffsetToShelf(
-              applist_button_bounds,
-              Shelf::ForWindow(container)->GetAppListButtonView()->GetWidget()),
-          GetBubbleArrow(container),
-          true /* border_accepts_events */);
-      view->SetArrowPaintType(views::BubbleBorder::PAINT_NONE);
-    }
+    app_list::AppListView* view = new app_list::AppListView(view_delegate_);
+    layout_delegate_.reset(new ash::AppListLayoutDelegate(this));
+    layout_delegate_->Init(view, root_window, current_apps_page_);
     SetView(view);
-    // By setting us as DnD recipient, the app list knows that we can
-    // handle items.
-    SetDragAndDropHostOfCurrentAppList(
-        Shelf::ForWindow(window)->GetDragAndDropHostForAppList());
   }
-  // Update applist button status when app list visibility is changed.
-  Shelf::ForWindow(window)->GetAppListButtonView()->SchedulePaint();
+  layout_delegate_->OnShown(root_window);
 }
 
-void AppListController::Dismiss() {
+void AppListShowerAsh::Dismiss() {
   if (!is_visible_)
     return;
 
   // If the app list is currently visible, there should be an existing view.
   DCHECK(view_);
 
   is_visible_ = false;
 
-  // App list needs to know the new shelf layout in order to calculate its
-  // UI layout when AppListView visibility changes.
-  Shell::GetPrimaryRootWindowController()
-      ->GetShelfLayoutManager()
-      ->UpdateAutoHideState();
-
   // Our widget is currently active. When the animation completes we'll hide
   // the widget, changing activation. If a menu is shown before the animation
   // completes then the activation change triggers the menu to close. By
   // deactivating now we ensure there is no activation change when the
   // animation completes and any menus stay open.
   view_->GetWidget()->Deactivate();
+
+  layout_delegate_->OnDismissed();
   ScheduleAnimation();
-
-  // Update applist button status when app list visibility is changed.
-  Shelf::ForWindow(view_->GetWidget()->GetNativeView())
-      ->GetAppListButtonView()
-      ->SchedulePaint();
 }
 
-bool AppListController::IsVisible() const {
+bool AppListShowerAsh::IsVisible() const {
   return view_ && view_->GetWidget()->IsVisible();
 }
 
-aura::Window* AppListController::GetWindow() {
-  return is_visible_ && view_ ? view_->GetWidget()->GetNativeWindow() : NULL;
+bool AppListShowerAsh::GetTargetVisibility() const {
+  return is_visible_;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController, private:
+// AppListShowerAsh, private:
 
-void AppListController::SetDragAndDropHostOfCurrentAppList(
-    app_list::ApplicationDragAndDropHost* drag_and_drop_host) {
-  if (view_ && is_visible_)
-    view_->SetDragAndDropHostOfCurrentAppList(drag_and_drop_host);
-}
-
-void AppListController::SetView(app_list::AppListView* view) {
-  DCHECK(view_ == NULL);
+void AppListShowerAsh::SetView(app_list::AppListView* view) {
+  DCHECK(view_ == nullptr);
   DCHECK(is_visible_);
 
   view_ = view;
   views::Widget* widget = view_->GetWidget();
   widget->AddObserver(this);
   keyboard::KeyboardController* keyboard_controller =
       keyboard::KeyboardController::GetInstance();
   if (keyboard_controller)
     keyboard_controller->AddObserver(this);
-  Shell::GetInstance()->AddPreTargetHandler(this);
-  Shelf::ForWindow(widget->GetNativeWindow())->AddIconObserver(this);
   widget->GetNativeView()->GetRootWindow()->AddObserver(this);
   aura::client::GetFocusClient(widget->GetNativeView())->AddObserver(this);
-
   view_->GetAppsPaginationModel()->AddObserver(this);
-
   view_->ShowWhenReady();
 }
 
-void AppListController::ResetView() {
+void AppListShowerAsh::ResetView() {
   if (!view_)
     return;
 
   views::Widget* widget = view_->GetWidget();
   widget->RemoveObserver(this);
   GetLayer(widget)->GetAnimator()->RemoveObserver(this);
   keyboard::KeyboardController* keyboard_controller =
       keyboard::KeyboardController::GetInstance();
   if (keyboard_controller)
     keyboard_controller->RemoveObserver(this);
-  Shell::GetInstance()->RemovePreTargetHandler(this);
-  Shelf::ForWindow(widget->GetNativeWindow())->RemoveIconObserver(this);
+  // Don't keep the layout delegate around when we don't need it - this way
+  // we don't need to worry about what listeners the layout delegate registers,
+  // and shutting them down in the proper order during shell shutdown.
+  layout_delegate_.reset();
   widget->GetNativeView()->GetRootWindow()->RemoveObserver(this);
   aura::client::GetFocusClient(widget->GetNativeView())->RemoveObserver(this);
 
   view_->GetAppsPaginationModel()->RemoveObserver(this);
 
-  view_ = NULL;
+  view_ = nullptr;
 }
 
-void AppListController::ScheduleAnimation() {
+void AppListShowerAsh::ScheduleAnimation() {
   // Stop observing previous animation.
   StopObservingImplicitAnimations();
 
   views::Widget* widget = view_->GetWidget();
   ui::Layer* layer = GetLayer(widget);
   layer->GetAnimator()->StopAnimating();
 
   gfx::Rect target_bounds;
+  gfx::Vector2d offset = layout_delegate_->GetVisibilityAnimationOffset(
+      widget->GetNativeView()->GetRootWindow());
   if (is_visible_) {
     target_bounds = widget->GetWindowBoundsInScreen();
-    widget->SetBounds(OffsetTowardsShelf(target_bounds, widget));
+    gfx::Rect start_bounds = gfx::Rect(target_bounds);
+    start_bounds.Offset(offset);
+    widget->SetBounds(start_bounds);
   } else {
-    target_bounds = OffsetTowardsShelf(widget->GetWindowBoundsInScreen(),
-                                       widget);
+    target_bounds = widget->GetWindowBoundsInScreen();
+    target_bounds.Offset(offset);
   }
 
   ui::ScopedLayerAnimationSettings animation(layer->GetAnimator());
-  animation.SetTransitionDuration(
-      base::TimeDelta::FromMilliseconds(
-          is_visible_ ? 0 : kAnimationDurationMs));
+  animation.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
+      is_visible_ ? 0 : kAnimationDurationMs));
   animation.AddObserver(this);
 
   layer->SetOpacity(is_visible_ ? 1.0 : 0.0);
   widget->SetBounds(target_bounds);
 }
 
-void AppListController::ProcessLocatedEvent(ui::LocatedEvent* event) {
-  if (!view_ || !is_visible_)
-    return;
+////////////////////////////////////////////////////////////////////////////////
+// AppListShowerAsh,  aura::FocusObserver implementation:
 
-  // If the event happened on a menu, then the event should not close the app
-  // list.
-  aura::Window* target = static_cast<aura::Window*>(event->target());
-  if (target) {
-    RootWindowController* root_controller =
-        GetRootWindowController(target->GetRootWindow());
-    if (root_controller) {
-      aura::Window* menu_container =
-          root_controller->GetContainer(kShellWindowId_MenuContainer);
-      if (menu_container->Contains(target))
-        return;
-      aura::Window* keyboard_container = root_controller->GetContainer(
-          kShellWindowId_VirtualKeyboardContainer);
-      if (keyboard_container->Contains(target))
-        return;
-    }
-  }
-
-  aura::Window* window = view_->GetWidget()->GetNativeView()->parent();
-  if (!window->Contains(target) &&
-      !app_list::switches::ShouldNotDismissOnBlur()) {
-    Dismiss();
-  }
-}
-
-void AppListController::UpdateBounds() {
-  if (!view_ || !is_visible_)
-    return;
-
-  view_->UpdateBounds();
-
-  if (is_centered_)
-    view_->SetAnchorPoint(GetCenterOfDisplayForView(
-        view_, GetMinimumBoundsHeightForAppList(view_)));
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, aura::EventFilter implementation:
-
-void AppListController::OnMouseEvent(ui::MouseEvent* event) {
-  if (event->type() == ui::ET_MOUSE_PRESSED)
-    ProcessLocatedEvent(event);
-}
-
-void AppListController::OnGestureEvent(ui::GestureEvent* event) {
-  if (event->type() == ui::ET_GESTURE_TAP_DOWN)
-    ProcessLocatedEvent(event);
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController,  aura::FocusObserver implementation:
-
-void AppListController::OnWindowFocused(aura::Window* gained_focus,
-                                        aura::Window* lost_focus) {
+void AppListShowerAsh::OnWindowFocused(aura::Window* gained_focus,
+                                       aura::Window* lost_focus) {
   if (view_ && is_visible_) {
     aura::Window* applist_window = view_->GetWidget()->GetNativeView();
     aura::Window* applist_container = applist_window->parent();
 
     if (applist_container->Contains(lost_focus) &&
         (!gained_focus || !applist_container->Contains(gained_focus)) &&
         !app_list::switches::ShouldNotDismissOnBlur()) {
       Dismiss();
     }
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController,  aura::WindowObserver implementation:
-void AppListController::OnWindowBoundsChanged(aura::Window* root,
-                                              const gfx::Rect& old_bounds,
-                                              const gfx::Rect& new_bounds) {
-  UpdateBounds();
+// AppListShowerAsh,  aura::WindowObserver implementation:
+void AppListShowerAsh::OnWindowBoundsChanged(aura::Window* root,
+                                             const gfx::Rect& old_bounds,
+                                             const gfx::Rect& new_bounds) {
+  if (layout_delegate_)
+    layout_delegate_->UpdateBounds();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController, ui::ImplicitAnimationObserver implementation:
+// AppListShowerAsh, ui::ImplicitAnimationObserver implementation:
 
-void AppListController::OnImplicitAnimationsCompleted() {
-  if (is_visible_ )
+void AppListShowerAsh::OnImplicitAnimationsCompleted() {
+  if (is_visible_)
     view_->GetWidget()->Activate();
   else
     view_->GetWidget()->Close();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController, views::WidgetObserver implementation:
+// AppListShowerAsh, views::WidgetObserver implementation:
 
-void AppListController::OnWidgetDestroying(views::Widget* widget) {
+void AppListShowerAsh::OnWidgetDestroying(views::Widget* widget) {
   DCHECK(view_->GetWidget() == widget);
   if (is_visible_)
     Dismiss();
   ResetView();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController, keyboard::KeyboardControllerObserver implementation:
+// AppListShowerAsh, keyboard::KeyboardControllerObserver implementation:
 
-void AppListController::OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) {
-  UpdateBounds();
+void AppListShowerAsh::OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) {
+  if (layout_delegate_)
+    layout_delegate_->UpdateBounds();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController, ShellObserver implementation:
-void AppListController::OnShelfAlignmentChanged(aura::Window* root_window) {
-  if (view_)
-    view_->SetBubbleArrow(GetBubbleArrow(view_->GetWidget()->GetNativeView()));
-}
+// AppListShowerAsh, PaginationModelObserver implementation:
 
-void AppListController::OnMaximizeModeStarted() {
-  // The "fullscreen" app-list is initialized as in a different type of window,
-  // therefore we can't switch between the fullscreen status and the normal
-  // app-list bubble. App-list should be dismissed for the transition between
-  // maximize mode (touch-view mode) and non-maximize mode, otherwise the app
-  // list tries to behave as a bubble which leads to a crash. crbug.com/510062
-  if (IsFullscreenAppListEnabled() && is_visible_)
-    Dismiss();
-}
+void AppListShowerAsh::TotalPagesChanged() {}
 
-void AppListController::OnMaximizeModeEnded() {
-  // See the comments of OnMaximizeModeStarted().
-  if (IsFullscreenAppListEnabled() && is_visible_)
-    Dismiss();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, ShelfIconObserver implementation:
-
-void AppListController::OnShelfIconPositionsChanged() {
-  UpdateBounds();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, PaginationModelObserver implementation:
-
-void AppListController::TotalPagesChanged() {
-}
-
-void AppListController::SelectedPageChanged(int old_selected,
-                                            int new_selected) {
+void AppListShowerAsh::SelectedPageChanged(int old_selected, int new_selected) {
   current_apps_page_ = new_selected;
 }
 
-void AppListController::TransitionStarted() {
-}
+void AppListShowerAsh::TransitionStarted() {}
 
-void AppListController::TransitionChanged() {
+void AppListShowerAsh::TransitionChanged() {
   // |view_| could be NULL when app list is closed with a running transition.
   if (!view_)
     return;
 
   app_list::PaginationModel* pagination_model = view_->GetAppsPaginationModel();
 
   const app_list::PaginationModel::Transition& transition =
       pagination_model->transition();
   if (pagination_model->is_valid_page(transition.target_page))
     return;
 
   views::Widget* widget = view_->GetWidget();
-  ui::LayerAnimator* widget_animator = GetLayer(widget)->GetAnimator();
+  ui::LayerAnimator* widget_animator =
+      widget->GetNativeView()->layer()->GetAnimator();
   if (!pagination_model->IsRevertingCurrentTransition()) {
     // Update cached |view_bounds_| if it is the first over-scroll move and
     // widget does not have running animations.
     if (!should_snap_back_ && !widget_animator->is_animating())
       view_bounds_ = widget->GetWindowBoundsInScreen();
 
     const int current_page = pagination_model->selected_page();
     const int dir = transition.target_page > current_page ? -1 : 1;
 
     const double progress = 1.0 - pow(1.0 - transition.progress, 4);
     const int shift = kMaxOverScrollShift * progress * dir;
 
     gfx::Rect shifted(view_bounds_);
     shifted.set_x(shifted.x() + shift);
 
     widget->SetBounds(shifted);
 
     should_snap_back_ = true;
   } else if (should_snap_back_) {
     should_snap_back_ = false;
     ui::ScopedLayerAnimationSettings animation(widget_animator);
     animation.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
         app_list::kOverscrollPageTransitionDurationMs));
     widget->SetBounds(view_bounds_);
   }
 }
-
-}  // namespace ash