[cros] Go back to EASE_OUT for boot transition

ash/wm/window_animations.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/window_animations.h"
 
 #include <math.h>
 
 #include <algorithm>
 #include <vector>
@@ skipping 494 matching lines @@
   }
 
   window->layer()->SetLayerBrightness(start_value);
   window->layer()->SetLayerGrayscale(start_value);
   if (show) {
     window->layer()->SetOpacity(kWindowAnimation_ShowOpacity);
     window->layer()->SetVisible(true);
   }
 
   int animation_duration = kBrightnessGrayscaleFadeDurationMs;
-  ui::Tween::Type animation_type = ui::Tween::EASE_OUT_2;
+  ui::Tween::Type animation_type = ui::Tween::EASE_OUT;
   if (CommandLine::ForCurrentProcess()->HasSwitch(
-          ash::switches::kAshDisableBootAnimation2)) {
-    animation_type = ui::Tween::EASE_OUT;
+          ash::switches::kAshBootAnimationFunction2)) {
+    animation_type = ui::Tween::EASE_OUT_2;
+  } else if (CommandLine::ForCurrentProcess()->HasSwitch(
+                  ash::switches::kAshBootAnimationFunction3)) {
+    animation_type = ui::Tween::EASE_OUT_3;
   }
 
   ui::ScopedLayerAnimationSettings settings(window->layer()->GetAnimator());
   settings.SetTransitionDuration(
       base::TimeDelta::FromMilliseconds(animation_duration));
   if (!show)
     settings.AddObserver(new HidingWindowAnimationObserver(window));
 
   scoped_ptr<ui::LayerAnimationSequence> brightness_sequence(
       new ui::LayerAnimationSequence());
@@ skipping 632 matching lines @@
     return AnimateShowWindow(window);
   } else {
     // Don't start hiding the window again if it's already being hidden.
     return window->layer()->GetTargetOpacity() != 0.0f &&
         AnimateHideWindow(window);
   }
 }
 
 }  // namespace internal
 }  // namespace ash