Unregister host if we fail to start it.

remoting/webapp/host_controller.js

Index: remoting/webapp/host_controller.js
diff --git a/remoting/webapp/host_controller.js b/remoting/webapp/host_controller.js
index e3ab141a9e83a606f981bcceae9e36820e795f2f..1b7a81118688426d63d5f5ef610bbcb57ba61c16 100644
--- a/remoting/webapp/host_controller.js
+++ b/remoting/webapp/host_controller.js
@@ -138,6 +138,9 @@ remoting.HostController.prototype.start = function(hostPin, callback) {
       localHost.status = 'ONLINE';
       that.setHost(localHost);
       remoting.hostList.addHost(localHost);
+    } else {
+      // Unregister the host if we failed to start it.
+      remoting.HostList.unregisterHostById(newHostId);
     }
     callback(result);
   };