ui::Layer::SwitchToLayer should finish animations on its old cc::Layer

ui/compositor/layer_unittest.cc

Index: ui/compositor/layer_unittest.cc
diff --git a/ui/compositor/layer_unittest.cc b/ui/compositor/layer_unittest.cc
index 378af34d7dd6fe512eafd0867c2c7b463dc8771e..e6ad58af64b0cc551b5482b185b8e3fbb43c271d 100644
--- a/ui/compositor/layer_unittest.cc
+++ b/ui/compositor/layer_unittest.cc
@@ -326,6 +326,7 @@ class TestCompositorObserver : public CompositorObserver {
 #define MAYBE_ScaleReparent DISABLED_ScaleReparent
 #define MAYBE_NoScaleCanvas DISABLED_NoScaleCanvas
 #define MAYBE_AddRemoveThreadedAnimations DISABLED_AddRemoveThreadedAnimations
+#define MAYBE_SwitchCCLayerAnimations DISABLED_SwitchCCLayerAnimations
 #else
 #define MAYBE_Delegate Delegate
 #define MAYBE_Draw Draw
@@ -341,6 +342,7 @@ class TestCompositorObserver : public CompositorObserver {
 #define MAYBE_ScaleReparent ScaleReparent
 #define MAYBE_NoScaleCanvas NoScaleCanvas
 #define MAYBE_AddRemoveThreadedAnimations AddRemoveThreadedAnimations
+#define MAYBE_SwitchCCLayerAnimations SwitchCCLayerAnimations
 #endif
 
 TEST_F(LayerWithRealCompositorTest, MAYBE_Draw) {
@@ -1358,4 +1360,26 @@ TEST_F(LayerWithRealCompositorTest, MAYBE_AddRemoveThreadedAnimations) {
   EXPECT_FALSE(l2->HasPendingThreadedAnimations());
 }
 
+// Tests that in-progress threaded animations complete when a Layer's
+// cc::Layer changes.
+TEST_F(LayerWithRealCompositorTest, MAYBE_SwitchCCLayerAnimations) {
+  scoped_ptr<Layer> root(CreateLayer(LAYER_TEXTURED));
+  scoped_ptr<Layer> l1(CreateLayer(LAYER_TEXTURED));
+  GetCompositor()->SetRootLayer(root.get());
+  root->Add(l1.get());
+
+  l1->SetAnimator(LayerAnimator::CreateImplicitAnimator());
+
+  EXPECT_FLOAT_EQ(l1->opacity(), 1.0f);
+
+  // Trigger a threaded animation.
+  l1->SetOpacity(0.5f);
+
+  // Change l1's cc::Layer.
+  l1->SwitchCCLayerForTest();
+
+  // Ensure that the opacity animation completed.
+  EXPECT_FLOAT_EQ(l1->opacity(), 0.5f);
+}
+
 }  // namespace ui