Revert of Remove support for GlobalNetworkClientFactory from RequestTracker.

ios/net/crn_http_protocol_handler.mm

Index: ios/net/crn_http_protocol_handler.mm
diff --git a/ios/net/crn_http_protocol_handler.mm b/ios/net/crn_http_protocol_handler.mm
index c9101f32a091df6f641f13d0938cdbe30a496e0f..d2855b4e2aebe73594100d0c81cdb470557ab22d 100644
--- a/ios/net/crn_http_protocol_handler.mm
+++ b/ios/net/crn_http_protocol_handler.mm
@@ -663,6 +663,11 @@
   if (tracker_) {
     // Set up any clients that can operate regardless of the request
     PushClients(tracker_->ClientsHandlingAnyRequest());
+  } else {
+    // There was no request_group_id, so the request was from something like a
+    // data: or file: URL.
+    // Attach any global clients to the request.
+    PushClients(RequestTracker::GlobalClientsHandlingAnyRequest());
   }
 
   // Now that all of the network clients are set up, if there was an error with