Pepper: Add tests for the PPB_NetAddress_Private interface.

ppapi/cpp/private/net_address_private.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 PPAPI_CPP_PRIVATE_NET_ADDRESS_PRIVATE_H_
 #define PPAPI_CPP_PRIVATE_NET_ADDRESS_PRIVATE_H_
 
 #include <string>
 
 #include "ppapi/c/pp_stdint.h"
 
 struct PP_NetAddress_Private;
 
 namespace pp {
 
 class NetAddressPrivate {
  public:
+  // Returns true if the required interface is available.
+  static bool IsAvailable();
+
   static bool AreEqual(const PP_NetAddress_Private& addr1,
                        const PP_NetAddress_Private& addr2);
   static bool AreHostsEqual(const PP_NetAddress_Private& addr1,
                             const PP_NetAddress_Private& addr2);
   static std::string Describe(const PP_NetAddress_Private& addr,
                               bool include_port);
   static bool ReplacePort(const PP_NetAddress_Private& addr_in,
                           uint16_t port,
                           PP_NetAddress_Private* addr_out);
   static void GetAnyAddress(bool is_ipv6, PP_NetAddress_Private* addr);
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_PRIVATE_NET_ADDRESS_PRIVATE_H_