Blink Compositor Animation: Introduce CompositorAnimationHost correctly.

third_party/WebKit/Source/platform/animation/CompositorAnimationHostTest.cpp

 // Copyright 2016 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 "platform/animation/CompositorAnimationHost.h"
 
 #include "base/memory/ref_counted.h"
 #include "platform/animation/CompositorAnimationTimeline.h"
 #include "platform/testing/CompositorTest.h"
 #include "platform/testing/WebLayerTreeViewImplForTesting.h"
 #include "wtf/PtrUtil.h"
 #include <memory>
 
 namespace blink {
 
 class CompositorAnimationHostTest : public CompositorTest {};
 
 TEST_F(CompositorAnimationHostTest, AnimationHostNullWhenTimelineDetached) {
   std::unique_ptr<CompositorAnimationTimeline> timeline =
       CompositorAnimationTimeline::create();
 
   scoped_refptr<cc::AnimationTimeline> ccTimeline =
       timeline->animationTimeline();
   EXPECT_FALSE(ccTimeline->animation_host());
-  EXPECT_TRUE(timeline->compositorAnimationHost().isNull());
 
   std::unique_ptr<WebLayerTreeView> layerTreeHost =
       WTF::wrapUnique(new WebLayerTreeViewImplForTesting);
   DCHECK(layerTreeHost);
 
-  layerTreeHost->attachCompositorAnimationTimeline(
-      timeline->animationTimeline());
-  EXPECT_FALSE(timeline->compositorAnimationHost().isNull());
+  auto compositorAnimationHost = WTF::makeUnique<CompositorAnimationHost>(
+      layerTreeHost->compositorAnimationHost());
 
-  layerTreeHost->detachCompositorAnimationTimeline(
-      timeline->animationTimeline());
-  EXPECT_TRUE(timeline->compositorAnimationHost().isNull());
+  compositorAnimationHost->addTimeline(timeline.get());
+  EXPECT_TRUE(ccTimeline->animation_host());
+
+  compositorAnimationHost->removeTimeline(timeline.get());
+  EXPECT_FALSE(ccTimeline->animation_host());
 }
 
 }  // namespace blink