[ash] Cleanup of ScopedOverviewAnimationSettings

ash/wm/overview/window_grid.cc

Index: ash/wm/overview/window_grid.cc
diff --git a/ash/wm/overview/window_grid.cc b/ash/wm/overview/window_grid.cc
index f415ffb026b6a6ce68c945f066f6523a87f1d87e..c1d882bf7d9b330b2dcdf68195e386317ac21f77 100644
--- a/ash/wm/overview/window_grid.cc
+++ b/ash/wm/overview/window_grid.cc
@@ -50,20 +50,6 @@
 namespace ash {
 namespace {
 
-using Windows = aura::Window::Windows;
-
-// A comparator for locating a given target window.
-struct WindowSelectorItemComparator {
-  explicit WindowSelectorItemComparator(const aura::Window* target_window)
-      : target(target_window) {}
-
-  bool operator()(std::unique_ptr<WindowSelectorItem>& window) const {
-    return window->GetWindow() == target;
-  }
-
-  const aura::Window* target;
-};
-
 // Time it takes for the selector widget to move to the next target. The same
 // time is used for fading out shield widget when the overview mode is opened
 // or closed.
@@ -569,8 +555,9 @@ void WindowGrid::OnWindowDestroying(aura::Window* window) {
   window_observer_.Remove(window);
   window_state_observer_.Remove(wm::GetWindowState(window));
   auto iter = std::find_if(window_list_.begin(), window_list_.end(),
-                           WindowSelectorItemComparator(window));
-
+                           [window](std::unique_ptr<WindowSelectorItem>& item) {
+                             return item->GetWindow() == window;
+                           });
   DCHECK(iter != window_list_.end());
 
   size_t removed_index = iter - window_list_.begin();
@@ -605,7 +592,9 @@ void WindowGrid::OnWindowBoundsChanged(aura::Window* window,
     return;
 
   auto iter = std::find_if(window_list_.begin(), window_list_.end(),
-                           WindowSelectorItemComparator(window));
+                           [window](std::unique_ptr<WindowSelectorItem>& item) {
+                             return item->GetWindow() == window;
+                           });
   DCHECK(iter != window_list_.end());
 
   // Immediately finish any active bounds animation.