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 282642e05ed59e100f62299c92d5626c19a55bf0..c8f4f9ba26ce36a20be66b10d2a3756811f39c30 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -4307,6 +4307,12 @@ void WebViewImpl::scheduleAnimation()
         m_client->scheduleAnimation();
 }
 
+void WebViewImpl::setCompositorAnimationTimeline(WebCompositorAnimationTimeline* timeline)
+{
+    if (m_layerTreeView)
+        m_layerTreeView->setCompositorAnimationTimeline(timeline);
+}
+
 void WebViewImpl::initializeLayerTreeView()
 {
     if (m_client) {