allowing ASGI to use drf_request in DjangoRequestExtractor (#3572)

since we already have patched a request object (both ASGI/WSGI) before arriving, we should move patched-using logic closer to where it actually being used. for minimize impact and allow ASGI functionality.

---------

Co-authored-by: Ivana Kellyer <ivana.kellyer@sentry.io>

sentry_sdk/integrations/django/__init__.py

@@ -491,13 +491,6 @@ def wsgi_request_event_processor(event, hint):
             # We have a `asgi_request_event_processor` for this.
             return event
 
-        try:
-            drf_request = request._sentry_drf_request_backref()
-            if drf_request is not None:
-                request = drf_request
-        except AttributeError:
-            pass
-
         with capture_internal_exceptions():
             DjangoRequestExtractor(request).extract_into_event(event)
 
@@ -530,6 +523,16 @@ def _got_request_exception(request=None, **kwargs):
 
 
 class DjangoRequestExtractor(RequestExtractor):
+    def __init__(self, request):
+        # type: (Union[WSGIRequest, ASGIRequest]) -> None
+        try:
+            drf_request = request._sentry_drf_request_backref()
+            if drf_request is not None:
+                request = drf_request
+        except AttributeError:
+            pass
+        self.request = request
+
     def env(self):
         # type: () -> Dict[str, str]
         return self.request.META