Merge "Add missing header" am: 4a6fd93492

Original change: https://android-review.googlesource.com/c/platform/system/libhidl/+/2469603

Change-Id: Ida5f28d2765daf5f9a480b56f1a531ac1d121611
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/base/include/hidl/TaskRunner.h b/base/include/hidl/TaskRunner.h
index 6a79ebf..f3ea92f 100644
--- a/base/include/hidl/TaskRunner.h
+++ b/base/include/hidl/TaskRunner.h
@@ -16,6 +16,7 @@
 #ifndef ANDROID_HIDL_TASK_RUNNER_H
 #define ANDROID_HIDL_TASK_RUNNER_H
 
+#include <functional>
 #include <memory>
 #include <thread>