Allow URLRequests from one context to have different NetworkDelegates.

net/url_request/url_request_test_util.cc

Index: net/url_request/url_request_test_util.cc
diff --git a/net/url_request/url_request_test_util.cc b/net/url_request/url_request_test_util.cc
index 03c189b8e119084c05370aac6981e9f6a2ce5575..668aa6c813538b3a867b6e901a25feef20c8ad41 100644
--- a/net/url_request/url_request_test_util.cc
+++ b/net/url_request/url_request_test_util.cc
@@ -134,7 +134,7 @@ TestURLRequest::TestURLRequest(const GURL& url,
                                RequestPriority priority,
                                Delegate* delegate,
                                TestURLRequestContext* context)
-    : URLRequest(url, priority, delegate, context) {}
+    : URLRequest(url, priority, delegate, context, NULL, NULL) {}
 
 TestURLRequest::~TestURLRequest() {
 }