Use a bitfield to store animatable properties.

ash/wm/overview/window_selector_panels.cc

 // Copyright 2013 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/overview/window_selector_panels.h"
 
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/overview/scoped_transform_overview_window.h"
@@ skipping 55 matching lines @@
   DCHECK(window()->parent()->id() == internal::kShellWindowId_PanelContainer);
   internal::PanelLayoutManager* panel_layout_manager =
       static_cast<internal::PanelLayoutManager*>(
           window()->parent()->layout_manager());
   return panel_layout_manager->GetCalloutWidgetForPanel(window());
 }
 
 void ScopedTransformPanelWindow::RestoreCallout() {
   scoped_ptr<ui::LayerAnimationSequence> sequence(
       new ui::LayerAnimationSequence);
-  ui::LayerAnimationElement::AnimatableProperties paused_properties;
-  paused_properties.insert(ui::LayerAnimationElement::OPACITY);
   sequence->AddElement(ui::LayerAnimationElement::CreatePauseElement(
-      paused_properties, base::TimeDelta::FromMilliseconds(
+      ui::LayerAnimationElement::OPACITY, base::TimeDelta::FromMilliseconds(
           ScopedTransformOverviewWindow::kTransitionMilliseconds)));
   sequence->AddElement(ui::LayerAnimationElement::CreateOpacityElement(1,
       base::TimeDelta::FromMilliseconds(
           kPanelCalloutFadeInDurationMilliseconds)));
   GetCalloutWidget()->GetLayer()->GetAnimator()->StartAnimation(
       sequence.release());
 }
 
 }  // namespace
 
@@ skipping 85 matching lines @@
     transform.Translate(bounding_rect.x() - bounds.x(),
                         bounding_rect.y() - bounds.y());
     transform.PreconcatTransform(bounding_transform);
     transform.Translate(bounds.x() - bounding_rect.x(),
                         bounds.y() - bounding_rect.y());
     (*iter)->SetTransform(root_window, transform, animate);
   }
 }
 
 }  // namespace ash