Import xlib.tx code from twisted proper

scrapy/core/downloader/handlers/http11.py

@@ -13,8 +13,9 @@ from twisted.web.http_headers import Headers as TxHeaders
 from twisted.web.iweb import IBodyProducer, UNKNOWN_LENGTH
 from twisted.internet.error import TimeoutError
 from twisted.web.http import PotentialDataLoss
-from scrapy.xlib.tx import Agent, ProxyAgent, ResponseDone, \
-    HTTPConnectionPool, TCP4ClientEndpoint
+from twisted.web.client import Agent, ProxyAgent, ResponseDone, \
+    HTTPConnectionPool
+from twisted.internet.endpoints import TCP4ClientEndpoint
 
 from scrapy.http import Headers
 from scrapy.responsetypes import responsetypes

scrapy/downloadermiddlewares/httpcache.py

@@ -3,10 +3,10 @@ from twisted.internet import defer
 from twisted.internet.error import TimeoutError, DNSLookupError, \
         ConnectionRefusedError, ConnectionDone, ConnectError, \
         ConnectionLost, TCPTimedOutError
+from twisted.web.client import ResponseFailed
 from scrapy import signals
 from scrapy.exceptions import NotConfigured, IgnoreRequest
 from scrapy.utils.misc import load_object
-from scrapy.xlib.tx import ResponseFailed
 
 
 class HttpCacheMiddleware(object):

scrapy/downloadermiddlewares/retry.py

@@ -17,10 +17,10 @@ from twisted.internet import defer
 from twisted.internet.error import TimeoutError, DNSLookupError, \
         ConnectionRefusedError, ConnectionDone, ConnectError, \
         ConnectionLost, TCPTimedOutError
+from twisted.web.client import ResponseFailed
 
 from scrapy.exceptions import NotConfigured
 from scrapy.utils.response import response_status_message
-from scrapy.xlib.tx import ResponseFailed
 from scrapy.core.downloader.handlers.http11 import TunnelError
 
 logger = logging.getLogger(__name__)

tests/test_downloadermiddleware_retry.py

@@ -3,10 +3,10 @@ from twisted.internet import defer
 from twisted.internet.error import TimeoutError, DNSLookupError, \
         ConnectionRefusedError, ConnectionDone, ConnectError, \
         ConnectionLost, TCPTimedOutError
+from twisted.web.client import ResponseFailed
 
 from scrapy import twisted_version
 from scrapy.downloadermiddlewares.retry import RetryMiddleware
-from scrapy.xlib.tx import ResponseFailed
 from scrapy.spiders import Spider
 from scrapy.http import Request, Response
 from scrapy.utils.test import get_crawler