VirtualEventBase is a SequencedExecutor

Summary:
VirtualEventBase is backed by a EventBase and byitself is also sequenced, thus shoudl be an SequencedExecutor

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum

Differential Revision: D21493098

fbshipit-source-id: 97fd09161117e77422a5786584db89af98dfe314

folly/io/async/VirtualEventBase.h

@@ -21,6 +21,7 @@
 #include <folly/Executor.h>
 #include <folly/Function.h>
 #include <folly/Synchronized.h>
+#include <folly/executors/SequencedExecutor.h>
 #include <folly/io/async/EventBase.h>
 #include <folly/synchronization/Baton.h>
 
@@ -38,7 +39,8 @@ namespace folly {
  * and all tasks scheduled through it are complete. EventBase destructor also
  * blocks until all VirtualEventBases backed by it are released.
  */
-class VirtualEventBase : public folly::Executor, public folly::TimeoutManager {
+class VirtualEventBase : public folly::TimeoutManager,
+                         public folly::SequencedExecutor {
  public:
   explicit VirtualEventBase(EventBase& evb);