Revert of Remove NPAPI plugin from chromoting webapp.

remoting/host/plugin/host_plugin_utils.h

+// Copyright (c) 2012 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 REMOTING_HOST_PLUGIN_HOST_PLUGIN_UTILS_H_
+#define REMOTING_HOST_PLUGIN_HOST_PLUGIN_UTILS_H_
+
+#include <string>
+
+#include "third_party/npapi/bindings/npapi.h"
+#include "third_party/npapi/bindings/npfunctions.h"
+#include "third_party/npapi/bindings/npruntime.h"
+
+namespace remoting {
+
+// Global netscape functions initialized in NP_Initialize.
+extern NPNetscapeFuncs* g_npnetscape_funcs;
+
+// Convert an NPIdentifier into a std::string.
+std::string StringFromNPIdentifier(NPIdentifier identifier);
+
+// Convert an NPVariant into a std::string.
+std::string StringFromNPVariant(const NPVariant& variant);
+
+// Convert a std::string into an NPVariant.
+// Caller is responsible for making sure that NPN_ReleaseVariantValue is
+// called on returned value.
+NPVariant NPVariantFromString(const std::string& val);
+
+// Convert an NPVariant into an NSPObject.
+NPObject* ObjectFromNPVariant(const NPVariant& variant);
+
+// Scoped reference pointer for NPObjects. All objects using this class
+// must be owned by g_npnetscape_funcs.
+class ScopedRefNPObject {
+ public:
+  ScopedRefNPObject();
+  explicit ScopedRefNPObject(NPObject* object);
+  explicit ScopedRefNPObject(const ScopedRefNPObject& object);
+  ~ScopedRefNPObject();
+
+  // Release the held reference and replace it with |object|, incrementing
+  // its reference count.
+  ScopedRefNPObject& operator=(NPObject* object);
+  ScopedRefNPObject& operator=(const ScopedRefNPObject& object);
+
+  NPObject* get() const { return object_; }
+
+ private:
+  NPObject* object_;
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_PLUGIN_HOST_PLUGIN_UTILS_H_