Introduce AnimationWorkletProxyClient and necessary plumbing to get it in worklet messaging proxy.

third_party/WebKit/Source/web/WebViewFrameWidget.cpp

Index: third_party/WebKit/Source/web/WebViewFrameWidget.cpp
diff --git a/third_party/WebKit/Source/web/WebViewFrameWidget.cpp b/third_party/WebKit/Source/web/WebViewFrameWidget.cpp
index 2e935aa649a0620727bc5c641ff1cf02233a8d6b..4f3ff528984104287675dfecfded2b2aef274f77 100644
--- a/third_party/WebKit/Source/web/WebViewFrameWidget.cpp
+++ b/third_party/WebKit/Source/web/WebViewFrameWidget.cpp
@@ -215,8 +215,14 @@ void WebViewFrameWidget::scheduleAnimation() {
   m_webView->scheduleAnimationForWidget();
 }
 
-CompositorProxyClient* WebViewFrameWidget::createCompositorProxyClient() {
-  return m_webView->createCompositorProxyClient();
+CompositorWorkerProxyClient*
+WebViewFrameWidget::createCompositorWorkerProxyClient() {
+  return m_webView->createCompositorWorkerProxyClient();
+}
+
+AnimationWorkletProxyClient*
+WebViewFrameWidget::createAnimationWorkletProxyClient() {
+  return m_webView->createAnimationWorkletProxyClient();
 }
 
 void WebViewFrameWidget::setRootGraphicsLayer(GraphicsLayer* layer) {