Expose worklet on Window through attribute renderWorklet.

third_party/WebKit/Source/modules/worklet/DOMWindowWorklet.h

Index: third_party/WebKit/Source/modules/worklet/DOMWindowWorklet.h
diff --git a/third_party/WebKit/Source/modules/worklet/DOMWindowWorklet.h b/third_party/WebKit/Source/modules/worklet/DOMWindowWorklet.h
new file mode 100644
index 0000000000000000000000000000000000000000..fe4589ebf8192f1550d166ecd440059fc271c8ad
--- /dev/null
+++ b/third_party/WebKit/Source/modules/worklet/DOMWindowWorklet.h
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+// 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.
+
+#ifndef DOMWindowWorklet_h
+#define DOMWindowWorklet_h
+
+#include "core/frame/DOMWindowProperty.h"
+#include "platform/Supplementable.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class DOMWindow;
+class ExecutionContext;
+class Worklet;
+
+class DOMWindowWorklet final : public NoBaseWillBeGarbageCollected<DOMWindowWorklet>, public WillBeHeapSupplement<LocalDOMWindow>, public DOMWindowProperty {
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(DOMWindowWorklet);
+    DECLARE_EMPTY_VIRTUAL_DESTRUCTOR_WILL_BE_REMOVED(DOMWindowWorklet);
+    USING_FAST_MALLOC_WILL_BE_REMOVED(DOMWindowWorklet);
+public:
+    static DOMWindowWorklet& from(LocalDOMWindow&);
+    static Worklet* renderWorklet(ExecutionContext*, DOMWindow&);
+    Worklet* renderWorklet(ExecutionContext*) const;
+
+    DECLARE_TRACE();
+
+private:
+    explicit DOMWindowWorklet(LocalDOMWindow&);
+    static const char* supplementName();
+
+    mutable PersistentWillBeMember<Worklet> m_renderWorklet;
+};
+
+} // namespace blink
+
+#endif // DOMWindowWorklet_h