Force async behavior for the virtual display output BufferQueue

Bug: 10551087
Change-Id: I40bbb2b87d64420939a0ea309254f281437dab56
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
index 4ab80e4..536007e 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
@@ -110,7 +110,7 @@
     //
     static Source fbSourceForCompositionType(CompositionType type);
     status_t dequeueBuffer(Source source, uint32_t format,
-            int* sslot, sp<Fence>* fence, bool async);
+            int* sslot, sp<Fence>* fence);
     void updateQueueBufferOutput(const QueueBufferOutput& qbo);
     void resetPerFrameState();
     status_t refreshOutputBuffer();