Allow URLRequests from one context to have different NetworkDelegates.

net/url_request/url_request_context.h

Index: net/url_request/url_request_context.h
diff --git a/net/url_request/url_request_context.h b/net/url_request/url_request_context.h
index 4e5873988e49d59651538a0e649e25107fd652be..992f985f0332b441af1c21614e27a5c48974cd4f 100644
--- a/net/url_request/url_request_context.h
+++ b/net/url_request/url_request_context.h
@@ -59,9 +59,8 @@ class NET_EXPORT URLRequestContext
   // May return NULL if this context doesn't have an associated network session.
   const HttpNetworkSession::Params* GetNetworkSessionParams() const;
 
-  // Creates a URLRequest. |cookie_store| optionally specifies a cookie store
-  // to be used rather than the one represented by the context, or NULL
-  // otherwise.
+  // Creates a URLRequest. If |cookie_store| is non-NULL, it will be used
+  // instead of the context's cookie store.
   scoped_ptr<URLRequest> CreateRequest(const GURL& url,
                                        RequestPriority priority,
                                        URLRequest::Delegate* delegate,