Animations: Introduce compositor AnimationPlayer and AnimationTimeline.

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 65d50b98ebeab6a8da58e802e7f243f99d40b551..5f1b98b7ed99c04ed22e278d51d23bb656d6137b 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -4239,6 +4239,18 @@ void WebViewImpl::scheduleAnimation()
         m_client->scheduleAnimation();
 }
 
+void WebViewImpl::attachCompositorAnimationTimeline(WebCompositorAnimationTimeline* timeline)
+{
+    if (m_layerTreeView)
+        m_layerTreeView->attachCompositorAnimationTimeline(timeline);
+}
+
+void WebViewImpl::detachCompositorAnimationTimeline(WebCompositorAnimationTimeline* timeline)
+{
+    if (m_layerTreeView)
+        m_layerTreeView->detachCompositorAnimationTimeline(timeline);
+}
+
 void WebViewImpl::initializeLayerTreeView()
 {
     if (m_client) {