Use a bitfield to store animatable properties.

ui/compositor/layer_animation_element_unittest.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 "ui/compositor/layer_animation_element.h"
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
@@ skipping 296 matching lines @@
   }
 
   LayerAnimationElement::TargetValue target_value(&delegate);
   element->GetTargetValue(&target_value);
   EXPECT_FLOAT_EQ(target, target_value.grayscale);
 }
 
 // Check that the pause element progresses the delegate as expected and
 // that the element can be reused after it completes.
 TEST(LayerAnimationElementTest, PauseElement) {
-  LayerAnimationElement::AnimatableProperties properties;
-  properties.insert(LayerAnimationElement::TRANSFORM);
-  properties.insert(LayerAnimationElement::BOUNDS);
-  properties.insert(LayerAnimationElement::OPACITY);
-  properties.insert(LayerAnimationElement::BRIGHTNESS);
-  properties.insert(LayerAnimationElement::GRAYSCALE);
+  LayerAnimationElement::AnimatableProperties properties =
+      LayerAnimationElement::TRANSFORM | LayerAnimationElement::BOUNDS |
+      LayerAnimationElement::OPACITY | LayerAnimationElement::BRIGHTNESS |
+      LayerAnimationElement::GRAYSCALE;
+
   base::TimeTicks start_time;
   base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
 
   scoped_ptr<LayerAnimationElement> element(
       LayerAnimationElement::CreatePauseElement(properties, delta));
 
   TestLayerAnimationDelegate delegate;
   TestLayerAnimationDelegate copy = delegate;
 
   start_time += delta;
@@ skipping 95 matching lines @@
   element->Abort(&delegate);
   target_transform.Blend(start_transform,
                          gfx::Tween::CalculateValue(tween_type, 0.5));
   CheckApproximatelyEqual(target_transform,
                           delegate.GetTransformForAnimation());
 }
 
 } // namespace
 
 } // namespace ui