overview: Remove unused WindowClosing functions.

Test: compiles
Bug: none
Change-Id: I7651e96e727110205740e0884550d559f9078abd
Reviewed-on: https://chromium-review.googlesource.com/1162582Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580653}

ash/wm/overview/window_grid.cc

@@ -517,15 +517,6 @@ void WindowGrid::FilterItems(const base::string16& pattern) {
   }
 }
 
-void WindowGrid::WindowClosing(WindowSelectorItem* window) {
-  if (!selection_widget_ || SelectedWindow() != window)
-    return;
-  aura::Window* selection_widget_window = selection_widget_->GetNativeWindow();
-  ScopedOverviewAnimationSettings animation_settings_label(
-      OVERVIEW_ANIMATION_CLOSING_SELECTOR_ITEM, selection_widget_window);
-  selection_widget_->SetOpacity(0.f);
-}
-
 void WindowGrid::SetBoundsAndUpdatePositions(const gfx::Rect& bounds) {
   SetBoundsAndUpdatePositionsIgnoringWindow(bounds, nullptr);
 }

ash/wm/overview/window_grid.h

@@ -105,11 +105,6 @@ class ASH_EXPORT WindowGrid : public aura::WindowObserver,
   // If |pattern| is empty, no item is dimmed.
   void FilterItems(const base::string16& pattern);
 
-  // Called when |window| is about to get closed. If the |window| is currently
-  // selected the implementation fades out |selection_widget_| to transparent
-  // opacity, effectively hiding the selector widget.
-  void WindowClosing(WindowSelectorItem* window);
-
   // Sets bounds for the window grid and positions all windows in the grid.
   void SetBoundsAndUpdatePositions(const gfx::Rect& bounds_in_screen);
   void SetBoundsAndUpdatePositionsIgnoringWindow(

ash/wm/overview/window_selector.cc

@@ -486,10 +486,6 @@ void WindowSelector::SelectWindow(WindowSelectorItem* item) {
   wm::GetWindowState(window)->Activate();
 }
 
-void WindowSelector::WindowClosing(WindowSelectorItem* window) {
-  grid_list_[selected_grid_index_]->WindowClosing(window);
-}
-
 void WindowSelector::SetBoundsForWindowGridsInScreenIgnoringWindow(
     const gfx::Rect& bounds,
     WindowSelectorItem* ignored_item) {

ash/wm/overview/window_selector.h

@@ -90,9 +90,6 @@ class ASH_EXPORT WindowSelector : public display::DisplayObserver,
   // Activates |item's| window.
   void SelectWindow(WindowSelectorItem* item);
 
-  // Called when |window| is about to get closed.
-  void WindowClosing(WindowSelectorItem* window);
-
   // Called to set bounds for window grids. Used for split view.
   void SetBoundsForWindowGridsInScreenIgnoringWindow(
       const gfx::Rect& bounds,