Revert of Remove header dependencies from sequence_checker.h to sequenced_worker_pool.h

chrome/browser/supervised_user/supervised_user_url_filter.h

Index: chrome/browser/supervised_user/supervised_user_url_filter.h
diff --git a/chrome/browser/supervised_user/supervised_user_url_filter.h b/chrome/browser/supervised_user/supervised_user_url_filter.h
index b1259f85b8e3940e31dc7f28235b419f8116fc62..0b34d37f47912678b09440bfab1f78c60623197f 100644
--- a/chrome/browser/supervised_user/supervised_user_url_filter.h
+++ b/chrome/browser/supervised_user/supervised_user_url_filter.h
@@ -25,13 +25,11 @@
 class GURL;
 class SupervisedUserBlacklist;
 
-namespace base {
-class TaskRunner;
-}
-
 namespace net {
 class URLRequestContextGetter;
 }
+
+class GURL;
 
 // This class manages the filtering behavior for a given URL, i.e. it tells
 // callers if a given URL should be allowed, blocked or warned about. It uses