ppapi: PPB_VpnProvider: Add a simple NaCl SDK example.

native_client_sdk/src/examples/api/vpn_provider/vpn_provider_helper.h

Index: native_client_sdk/src/examples/api/vpn_provider/vpn_provider_helper.h
diff --git a/native_client_sdk/src/examples/api/vpn_provider/vpn_provider_helper.h b/native_client_sdk/src/examples/api/vpn_provider/vpn_provider_helper.h
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index 0000000000000000000000000000000000000000..e2e359ea544c702734e755f829c5fa02e534a66d
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+++ b/native_client_sdk/src/examples/api/vpn_provider/vpn_provider_helper.h
@@ -0,0 +1,52 @@
+// 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 VPN_PROVIDER_HELPER_H_
+#define VPN_PROVIDER_HELPER_H_
+
+#include <stdint.h>
+
+#include <queue>
+#include <string>
+
+#include "ppapi/cpp/instance.h"
+#include "ppapi/cpp/var.h"
+#include "ppapi/cpp/vpn_provider.h"
+#include "ppapi/utility/completion_callback_factory.h"
+#include "ppapi/utility/threading/simple_thread.h"
+
+// Helper class that keeps VpnPacket handling in its own thread.
+class VpnProviderHelper {
+ public:
+  explicit VpnProviderHelper(pp::Instance* instance);
+
+  void Init();
+  void Bind(const std::string& config_name, const std::string& config_id);
+  void SendPacket(const pp::Var& data);
+
+ private:
+  void InitOnThread(int32_t result);
+  void BindOnThread(int32_t result,
+                    const std::string& config,
+                    const std::string& name);
+  void SendPacketOnThread(int32_t result, const pp::Var& data);
+
+  // Completion Callbacks
+  void BindCompletionCallback(int32_t result);
+  void ReceivePacketCompletionCallback(int32_t result, const pp::Var& packet);
+  void SendPacketCompletionCallback(int32_t result);
+
+  pp::Instance* instance_;
+  pp::SimpleThread thread_;
+  pp::VpnProvider vpn_;
+  pp::CompletionCallbackFactory<VpnProviderHelper> factory_;
+
+  bool send_packet_pending_;
+  std::queue<pp::Var> send_packet_queue_;
+
+  std::string config_name_;
+  std::string config_id_;
+};
+
+#endif