Revert 120092 - Reland 120074 -- Disable animations during aura tests.

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 "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
@@ skipping 153 matching lines @@
 }
 
 // Hides a window using an animation, animating its opacity from 1.f to 0.f, and
 // its transform to |end_transform|.
 void AnimateHideWindowCommon(aura::Window* window,
                              const ui::Transform& end_transform) {
   window->layer()->set_delegate(NULL);
 
   // Property sets within this scope will be implicitly animated.
   ui::ScopedLayerAnimationSettings settings(window->layer()->GetAnimator());
-  settings.AddObserver(new HidingWindowAnimationObserver(window));
-
+  settings.AddImplicitObserver(new HidingWindowAnimationObserver(window));
   int duration =
       window->GetIntProperty(internal::kWindowVisibilityAnimationDurationKey);
   if (duration > 0) {
     settings.SetTransitionDuration(
         base::TimeDelta::FromInternalValue(duration));
   }
 
   window->layer()->SetOpacity(kWindowAnimation_HideOpacity);
   window->layer()->SetTransform(end_transform);
 }
@@ skipping 93 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