[worklets] Add stub classes for window.animationWorklet

third_party/WebKit/Source/modules/compositorworker/AnimationWorklet.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 "modules/compositorworker/AnimationWorklet.h"
+
+#include "bindings/core/v8/V8Binding.h"
+#include "core/dom/ExecutionContext.h"
+#include "modules/worklet/ThreadedWorkletGlobalScopeProxy.h"
+
+namespace blink {
+
+// static
+AnimationWorklet* AnimationWorklet::create(ExecutionContext* executionContext)
+{
+    AnimationWorklet* worklet = new AnimationWorklet(executionContext);
+    worklet->suspendIfNeeded();
+    return worklet;
+}
+
+AnimationWorklet::AnimationWorklet(ExecutionContext* executionContext)
+    : Worklet(executionContext)
+    , m_workletGlobalScopeProxy(new ThreadedWorkletGlobalScopeProxy())
+{
+}
+
+AnimationWorklet::~AnimationWorklet()
+{
+}
+
+WorkletGlobalScopeProxy* AnimationWorklet::workletGlobalScopeProxy() const
+{
+    return m_workletGlobalScopeProxy.get();
+}
+
+DEFINE_TRACE(AnimationWorklet)
+{
+    Worklet::trace(visitor);
+}
+
+} // namespace blink