[remoting android] Display IT2Me host state and access-code.

remoting/host/android/jni_host.cc

 // 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.
 
 #include "remoting/host/android/jni_host.h"
 
 #include "base/android/jni_string.h"
 #include "base/command_line.h"
 #include "base/strings/string_util.h"
 #include "jni/Host_jni.h"
@@ skipping 74 matching lines @@
   std::string directory_bot_jid =
       ServiceUrls::GetInstance()->directory_bot_jid();
 
   // Create the It2Me host and start connecting.
   it2me_host_ = factory_->CreateIt2MeHost(host_context_->Copy(), weak_ptr_,
                                           xmpp_config, directory_bot_jid);
   it2me_host_->Connect();
 }
 
 void JniHost::Disconnect(JNIEnv* env,
-                         const base::android::JavaParamRef<jobject>& caller) {}
+                         const base::android::JavaParamRef<jobject>& caller) {
+  if (it2me_host_) {
+    it2me_host_->Disconnect();
+    it2me_host_ = nullptr;
+  }
+}
 
 void JniHost::OnClientAuthenticated(const std::string& client_username) {
   HOST_LOG << "OnClientAuthenticated: " << client_username;
 }
 
 void JniHost::OnStoreAccessCode(const std::string& access_code,
                                 base::TimeDelta access_code_lifetime) {
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_Host_onAccessCodeReceived(
       env, java_host_.obj(), ConvertUTF8ToJavaString(env, access_code).obj(),
       static_cast<int>(access_code_lifetime.InSeconds()));
 }
 
 void JniHost::OnNatPolicyChanged(bool nat_traversal_enabled) {
   HOST_LOG << "OnNatPolicyChanged: " << nat_traversal_enabled;
 }
 
 void JniHost::OnStateChanged(It2MeHostState state,
                              const std::string& error_message) {
+  if (state == kDisconnected) {
+    it2me_host_ = nullptr;
+  }
+
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_Host_onStateChanged(env, java_host_.obj(), state,
                            ConvertUTF8ToJavaString(env, error_message).obj());
 }
 
 static jlong Init(JNIEnv* env, const JavaParamRef<jobject>& caller) {
   return reinterpret_cast<intptr_t>(new JniHost(env, caller));
 }
 
 }  // namespace remoting