[Remoting Android] Fix GetWeakPtr() calls on multiple threads

remoting/client/jni/jni_pairing_secret_fetcher.h

 // 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 REMOTING_CLIENT_JNI_JNI_PAIRING_SECRET_FETCHER_H_
 #define REMOTING_CLIENT_JNI_JNI_PAIRING_SECRET_FETCHER_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "remoting/protocol/client_authentication_config.h"
@@ skipping 33 matching lines @@
 
   ChromotingJniRuntime* jni_runtime_;
   base::WeakPtr<JniClient> jni_client_;
 
   std::string host_id_;
 
   // Pass this the user's PIN once we have it. To be assigned and accessed on
   // the UI thread, but must be posted to the network thread to call it.
   protocol::SecretFetchedCallback callback_;
 
+  base::WeakPtr<JniPairingSecretFetcher> weak_ptr_;
   base::WeakPtrFactory<JniPairingSecretFetcher> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(JniPairingSecretFetcher);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_CLIENT_JNI_JNI_PAIRING_SECRET_FETCHER_H_