Revert "Delete HWC1"

This reverts commit 90f923493fa053655a203c34ea491086aeb07602.

Change-Id: If9da49e3bc85f8ff21ac1bd22a6bab97e9aa3103
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
index 884460d..70f717f 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
@@ -83,6 +83,9 @@
     //
     virtual status_t beginFrame(bool mustRecompose);
     virtual status_t prepareFrame(CompositionType compositionType);
+#ifndef USE_HWC2
+    virtual status_t compositionComplete();
+#endif
     virtual status_t advanceFrame();
     virtual void onFrameCommitted();
     virtual void dumpAsString(String8& result) const;