fix npe issue #81

plugins/org.chromium.sdk.wipbackend.dev/src/org/chromium/sdk/internal/wip/WipBackendImpl.java

 // 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.
 
 package org.chromium.sdk.internal.wip;
 
 import java.io.IOException;
 import java.io.OutputStream;
 import java.net.InetSocketAddress;
 import java.net.URI;
@@ skipping 107 matching lines @@
             Hybi17WsConnection.MaskStrategy.TRANSPARENT_MASK, connectionLogger);
       }
 
 
       return new WipTabImpl(socket, browserImpl, listener, description.url());
     }
   }
 
   private String readHttpResponseContent(InetSocketAddress socketAddress, String resource,
       LoggerFactory loggerFactory) throws IOException {
-    ConnectionLogger browserConnectionLogger = loggerFactory.newBrowserConnectionLogger();
+    ConnectionLogger browserConnectionLogger;
+    if (loggerFactory == null) {
+      browserConnectionLogger = null;
+    } else {
+      browserConnectionLogger = loggerFactory.newBrowserConnectionLogger();
+    }
     final SocketWrapper socketWrapper = new SocketWrapper(
         socketAddress, DEFAULT_CONNECTION_TIMEOUT_MS, browserConnectionLogger,
         HandshakeUtil.ASCII_CHARSET);
     try {
       if (browserConnectionLogger != null) {
         browserConnectionLogger.start();
         browserConnectionLogger.setConnectionCloser(new ConnectionLogger.ConnectionCloser() {
           @Override
           public void closeConnection() {
             socketWrapper.getShutdownRelay().sendSignal(null, new Exception("UI close request"));
@@ skipping 66 matching lines @@
 
     try {
       WipTabList tabList = WipParserAccess.get().parseTabList(jsonValue);
       return tabList.asTabList();
     } catch (JsonProtocolParseException e) {
       throw new IOException(
           "Failed to parse tab list response (on protocol level)", e);
     }
   }
 }