diff --git a/services/surfaceflinger/DispSync.h b/services/surfaceflinger/DispSync.h
index c4280aa..19eb3e5 100644
--- a/services/surfaceflinger/DispSync.h
+++ b/services/surfaceflinger/DispSync.h
@@ -99,6 +99,9 @@
     // DispSync object.
     status_t removeEventListener(const sp<Callback>& callback);
 
+    // dump appends human-readable debug info to the result string.
+    void dump(String8& result) const;
+
 private:
 
     void updateModelLocked();