Implement student-initiated refunds for external commerce service.

XCOM-306

common/djangoapps/request_cache/middleware.py

@@ -2,6 +2,7 @@ import threading
 
 _request_cache_threadlocal = threading.local()
 _request_cache_threadlocal.data = {}
+_request_cache_threadlocal.request = None
 
 
 class RequestCache(object):
@@ -9,11 +10,21 @@ class RequestCache(object):
     def get_request_cache(cls):
         return _request_cache_threadlocal
 
+    @classmethod
+    def get_current_request(cls):
+        """
+        Get a reference to the HttpRequest object, if we are presently
+        servicing one.
+        """
+        return _request_cache_threadlocal.request
+
     def clear_request_cache(self):
         _request_cache_threadlocal.data = {}
+        _request_cache_threadlocal.request = None
 
     def process_request(self, request):
         self.clear_request_cache()
+        _request_cache_threadlocal.request = request
         return None
 
     def process_response(self, request, response):