Begin to enable extension APIs in Extension Service Worker.

extensions/renderer/worker_thread_dispatcher.h

Index: extensions/renderer/worker_thread_dispatcher.h
diff --git a/extensions/renderer/worker_thread_dispatcher.h b/extensions/renderer/worker_thread_dispatcher.h
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+++ b/extensions/renderer/worker_thread_dispatcher.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 EXTENSIONS_RENDERER_WORKER_THREAD_DISPATCHER_H_
+#define EXTENSIONS_RENDERER_WORKER_THREAD_DISPATCHER_H_
+
+#include "base/synchronization/lock.h"
+#include "content/public/renderer/render_process_observer.h"
+#include "ipc/ipc_sync_message_filter.h"
+
+namespace base {
+class ListValue;
+}
+
+namespace content {
+class RenderThread;
+}
+
+namespace extensions {
+class RequestSender;
+class V8SchemaRegistry;
+
+// Sends and receives IPC in an extension Service Worker.
+// TODO(lazyboy): This class should really be a combination of the following
+// two:
+// 1) A content::WorkerThreadMessageFilter, so that we can receive IPC directly
+// on worker thread.
+// 2) A content::ThreadSafeSender, so we can safely send IPC from worker thread.
+class WorkerThreadDispatcher : public content::RenderProcessObserver {
+ public:
+  WorkerThreadDispatcher();
+  ~WorkerThreadDispatcher() override;
+
+  // Thread safe.
+  static WorkerThreadDispatcher* Get();
+  static RequestSender* GetRequestSender();
+
+  void Init(content::RenderThread* render_thread);
+  bool Send(IPC::Message* message);
+  void AddWorkerData(int embedded_worker_id);
+  void RemoveWorkerData(int embedded_worker_id);
+  V8SchemaRegistry* GetV8SchemaRegistry();
+
+ private:
+  // content::RenderProcessObserver:
+  bool OnControlMessageReceived(const IPC::Message& message) override;
+
+  // IPC handlers.
+  void OnResponseWorker(int worker_thread_id,
+                        int request_id,
+                        bool succeeded,
+                        const base::ListValue& response,
+                        const std::string& error);
+
+  // IPC sender. Belongs to the render thread, but thread safe.
+  scoped_refptr<IPC::SyncMessageFilter> message_filter_;
+
+  DISALLOW_COPY_AND_ASSIGN(WorkerThreadDispatcher);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_WORKER_THREAD_DISPATCHER_H_