[POC] Implement "module responses map" concept

third_party/WebKit/Source/core/workers/WorkletModuleResponsesMapProxy.h

+// Copyright 2017 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 WorkletModuleResponsesMapProxy_h
+#define WorkletModuleResponsesMapProxy_h
+
+#include "platform/heap/Heap.h"
+
+#include "core/CoreExport.h"
+#include "core/workers/WorkletModuleResponsesMap.h"
+#include "platform/WebTaskRunner.h"
+#include "platform/weborigin/KURL.h"
+#include "platform/wtf/Functional.h"
+#include "platform/wtf/Optional.h"
+
+namespace blink {
+
+class ModuleScriptCreationParams;
+
+// A proxy class to talk to WorkletModuleResponsesMap on the main thread from
+// WorkletGlobalScope on the worklet context thread. The constructor and all
+// public functions must be called on the worklet context thread.
+class CORE_EXPORT WorkletModuleResponsesMapProxy
+    : public GarbageCollectedFinalized<WorkletModuleResponsesMapProxy> {
+ public:
+  using Client = WorkletModuleResponsesMap::Client;
+  WorkletModuleResponsesMapProxy(
+      WorkletModuleResponsesMap*,
+      RefPtr<WebTaskRunner> outside_settings_task_runner,
+      RefPtr<WebTaskRunner> inside_settings_task_runner);
+
+  void ReadEntry(const KURL&, Client*);
+  void UpdateEntry(const KURL&, const ModuleScriptCreationParams&);
+  void InvalidateEntry(const KURL&);
+
+  DECLARE_TRACE();
+
+ private:
+  void ReadEntryOnMainThread(const KURL&, Client*);
+
+  CrossThreadPersistent<WorkletModuleResponsesMap> module_responses_map_;
+  RefPtr<WebTaskRunner> outside_settings_task_runner_;
+  RefPtr<WebTaskRunner> inside_settings_task_runner_;
+};
+
+}  // namespace blink
+
+#endif  // WorkletModuleResponsesMapProxy_h