Use ScopedRefNPObject to pass NPObjects in the host plugin.

remoting/host/plugin/host_plugin_utils.h

 // Copyright (c) 2011 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"
@@ skipping 18 matching lines @@
 
 // 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() { return object_; }
+  NPObject* get() const { return object_; }
 
  private:
   NPObject* object_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedRefNPObject);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_PLUGIN_HOST_PLUGIN_UTILS_H_