Use a bitfield to store animatable properties.

ui/compositor/layer_animation_element_unittest.cc

Index: ui/compositor/layer_animation_element_unittest.cc
diff --git a/ui/compositor/layer_animation_element_unittest.cc b/ui/compositor/layer_animation_element_unittest.cc
index 8871a2c9f5efee4c33741bd79e6c792c3de433e1..45de8d3fc55167e5768d801959fe2e09d5a6cf5a 100644
--- a/ui/compositor/layer_animation_element_unittest.cc
+++ b/ui/compositor/layer_animation_element_unittest.cc
@@ -314,12 +314,11 @@ TEST(LayerAnimationElementTest, GrayscaleElement) {
 // 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);