inputflinger: add missing <functional> include

Bug: 175635923
Test: treehugger
Change-Id: Ieb7828b26613c3b5470c9b76f31ad1b6b09d9445
Merged-In: Ieb7828b26613c3b5470c9b76f31ad1b6b09d9445
diff --git a/services/inputflinger/BlockingQueue.h b/services/inputflinger/BlockingQueue.h
index 8300e8a..032cb6d 100644
--- a/services/inputflinger/BlockingQueue.h
+++ b/services/inputflinger/BlockingQueue.h
@@ -17,10 +17,11 @@
 #ifndef _UI_INPUT_BLOCKING_QUEUE_H
 #define _UI_INPUT_BLOCKING_QUEUE_H
 
-#include "android-base/thread_annotations.h"
 #include <condition_variable>
+#include <functional>
 #include <mutex>
 #include <vector>
+#include "android-base/thread_annotations.h"
 
 namespace android {