Allow URLRequests from one context to have different NetworkDelegates.

mojo/services/network/url_loader_impl.cc

Index: mojo/services/network/url_loader_impl.cc
diff --git a/mojo/services/network/url_loader_impl.cc b/mojo/services/network/url_loader_impl.cc
index 810a7be3ba16dc77843a7e202d598a80b7955eb3..2f199dddca74f6ee2d3d9149c0d5bc4dac5db3e5 100644
--- a/mojo/services/network/url_loader_impl.cc
+++ b/mojo/services/network/url_loader_impl.cc
@@ -10,6 +10,7 @@
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_response_headers.h"
+#include "net/url_request/url_request_context.h"
 
 namespace mojo {
 namespace {
@@ -134,11 +135,11 @@ void URLLoaderImpl::Start(URLRequestPtr request,
     return;
   }
 
-  url_request_.reset(
-      new net::URLRequest(GURL(request->url),
-                          net::DEFAULT_PRIORITY,
-                          this,
-                          context_->url_request_context()));
+  url_request_ = context_->url_request_context()->CreateRequest(
+      GURL(request->url),
+      net::DEFAULT_PRIORITY,
+      this,
+      NULL);
   url_request_->set_method(request->method);
   if (request->headers) {
     net::HttpRequestHeaders headers;