Introduce WorkletGlobalScopeProxy interface.

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

Index: third_party/WebKit/Source/modules/worklet/ThreadedWorkletGlobalScope.h
diff --git a/third_party/WebKit/Source/modules/worklet/ThreadedWorkletGlobalScope.h b/third_party/WebKit/Source/modules/worklet/ThreadedWorkletGlobalScope.h
new file mode 100644
index 0000000000000000000000000000000000000000..688d3b38438993233aee61cc2473ed707fe170f9
--- /dev/null
+++ b/third_party/WebKit/Source/modules/worklet/ThreadedWorkletGlobalScope.h
@@ -0,0 +1,24 @@
+// 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 ThreadedWorkletGlobalScope_h
+#define ThreadedWorkletGlobalScope_h
+
+#include "core/workers/WorkletGlobalScope.h"
+
+namespace blink {
+
+class ThreadedWorkletGlobalScope : public WorkletGlobalScope {
+public:
+    ~ThreadedWorkletGlobalScope() override;
+
+    void addConsoleMessage(ConsoleMessage*) final;
+
+protected:
+    ThreadedWorkletGlobalScope(const KURL&, const String& userAgent, PassRefPtr<SecurityOrigin>, v8::Isolate*);
+};
+
+} // namespace blink
+
+#endif // ThreadedWorkletGlobalScope_h